By Michael Rushton, NFL Contributing Editor -- (Sports Network) - The Philadelphia Eagles have struggled in the red zone over the course of their two-game losing streak. Things won't get any easier this week, as the club could be without running back Brian Westbrook when it takes on the San Francisco 49ers Sunday at Candlestick Park.

The Eagles can look back to a pair of red-zone failures that have led to their slide, which has dropped them to 2-3 on the season. Two weeks ago against Chicago, when they playing without Westbrook due to an ankle injury, the Eagles were stopped late on four plays at the goal line in a 24-20 loss.

Then after having already blown a 14-0 lead versus the Washington Redskins last Sunday, the Eagles again failed to score a touchdown late in the fourth quarter despite being inside the five-yard line. Westbrook was stuffed on consecutive plays and Philadelphia had to settle for a field goal and a 23-17 deficit with 7:18 to play. That ended up being the final score of the game.

Westbrook returned from his ankle injury to run for just 33 yards and a touchdown while also catching six passes for 51 yards. However, he also suffered fractured ribs early on in the contest, though he stayed in the game. He was held out of practices this week and with a bye looming, it is possible that the running back will be rested this Sunday rather than risk further injury.

With a trio of four-game winners already in the NFC East, the Eagles can't afford to fall further behind in the division. The club is a game under .500 despite high rankings in both total offense and defense.

The 49ers have also lost two in a row and have struggled both offensively and defensively. After allowing 31 points in a loss to New Orleans in Week 4, the team was again tagged on the scoreboard in a 30-21 setback to the New England Patriots.

Quarterback J.T. O'Sullivan threw a career-high three touchdown passes, but was also intercepted three times against New England. He posted his second straight passer rating under 60, producing a 55.9 number versus the Patriots on the same day the 49ers retired Hall of Fame quarterback Steve Young's No. 8 jersey at halftime.

San Francisco is in the midst of a very tough four-game stretch in which it has lost the first two tests of that run. After taking on the Eagles, the Niners battle the defending Super Bowl champion New York Giants in the Big Apple on October 19.

O'Sullivan and his offensive line will first face a stiff test this weekend, as San Francisco has allowed an NFL-high 20 sacks and the Eagles are tied with Pittsburgh for the most sacks in the NFL with 18.

SERIES HISTORY

San Francisco holds a 16-9-1 lead in the all-time regular season series with Philadelphia, but have lost each of their last two meetings with the Eagles. The Birds were 38-24 winners when the teams last met, at Candlestick Park, in 2006. The Niners' most recent win in the series was a 31-28 overtime thriller in Philly in 2003. Philly is 2-0 in San Francisco since last losing there in 2001.

In addition to the regular season series, the clubs have met once in the postseason, with San Francisco earning a 14-0 victory in a 1996 NFC First- Round Playoff.

Eagles head coach Andy Reid is 3-2 against San Francisco in his career as a head coach, while San Francisco's Mike Nolan is 0-2 against both Reid and the Eagles.

WHEN THE EAGLES HAVE THE BALL

The Eagles' offense changes dramatically when Westbrook (194 rushing yards, 14 receptions, 6 total TD) is unavailable. The playmaking running back creates mismatches no matter where he lines up, giving the offense plenty of space to operate. If Westbrook can't go, running back Correll Buckhalter (114 rushing yards, 1 TD) would likely start in his place, with Lorenzo Booker also seeing time. Quarterback Donovan McNabb could be close to getting another weapon back though, as wide receiver Kevin Curtis was able to practice in full this week. Curtis has yet to play this season due to a sports hernia. McNabb (1,296 passing yards, 6 TD, 2 INT) threw for 196 yards versus the Redskins, matching his season low for fewest passing yards in a game. He also failed to throw a touchdown pass for the first time this year. Wideout Reggie Brown (10 receptions) was Philly's top receiver versus Washington with four catches for 84 yards, while tight end L.J. Smith (9 receptions, 1 TD) added three receptions for 26 yards. Brown was limited in practice due to a groin ailment, while Pro Bowl offensive guard Shawn Andrews is likely to sit out with a back injury that has kept him out of the last three games. Wideout DeSean Jackson (23 receptions, 1 TD), who leads the team and all NFL rookies with 335 receiving yards, returned a punt 68 yards for a score versus the Redskins.

The 49ers secondary draws the tough task of containing the Eagles' passing attack. The defense is ranked seventh in the NFC by allowing just 215.6 passing yards per game, while the team's seven interceptions are third in the conference. San Francisco held a Tom Brady-less Patriots offense to 233 net passing yards last weekend, while linebacker Takeo Spikes (33 tackles, 2 INT) and corner Nate Clements (19 tackles) each picked off a pass. Spikes, who started 14 games with the Eagles last year before being let go this past offseason, added 14 tackles in the loss, while linebacker and reigning Defensive Rookie of the Year Patrick Willis (46 tackles, 1 INT) posted 18 stops and a sack. Former Eagle safety Michael Lewis (35 tackles, 1 sack) added eight tackles versus New England, which was sacked by the 49ers five times. In addition to Willis, defensive ends Ray McDonald (17 tackles), Isaac Sopoaga (17 tackles) and Justin Smith (28 tackles, 3 sacks) each had a sack. Linebacker Manny Lawson, meanwhile, missed the New England game due to a hamstring ailment and is unlikely to play this weekend. The former first-round pick missed all but two games last year because of a torn ACL.

WHEN THE 49ERS HAVE THE BALL

O'Sullivan (1,092 passing yards, 7 TD, 6 INT) has begun to come back down to earth after a solid start. He threw for just 130 yards against New England and has thrown five of his six interceptions this year over the last two games. The Niners continue to rely on running back Frank Gore (180 rushing yards, 19 receptions, 4 total TD) to keep them in games. Like Westbrook, Gore gets it done on both the ground and through the air, as the back leads the NFL in yards from scrimmage with 603. He hauled in four passes for 24 yards and a score in Sunday's loss, while adding 54 rushing yards. The Miami-Florida product leads the club in both rushing and receptions. It is 35-year-old Isaac Bruce, though, that is the club's leader in receiving yards. Bruce (14 receptions, 4 TD) had three catches for 49 yards versus New England and caught two touchdown passes, his first multi-TD game as a member of San Francisco and the 13th of his career. The former longtime St. Louis Ram has hauled in a scoring pass in three straight games. Wideout Bryant Johnson (13 receptions, 1 TD) added three catches for 27 yards against the Pats, while starting tight end Vernon Davis has been held to just five catches all year and two over his last four games. He failed to post a catch versus New England.

The Eagles possess one of the top defenses in the conference, though they do have some injury concerns. The club is ranked fifth in the NFC in points allowed per game (19.4), third in both total yards allowed (274.0) and passing yards allowed (190.4) and fourth in rushing defense at 83.6 yards allowed per game. The club's rabid pass rush has helped those numbers, while Philly has also forced an NFC-high tying six fumbles this year. The 49ers know that all too well, as Eagles defensive tackle Mike Patterson had two fumble recoveries the last time these two clubs met, with the former first-round pick taking one a franchise-record 98 yards to the end zone. Patterson (16 tackles) had a team-high tying 10 tackles in the loss to the Redskins last weekend, as did linebacker Stewart Bradley (33 tackles, 1 sack). Safety Brian Dawkins (25 tackles, 2 sacks) had eight tackles and a sack, becoming the fifth defensive back in NFL history with 20 career sacks. However, the defensive unit, which allowed the Redskins to post 388 total yards, could be minus defensive end Juqua Parker (knee) and safety J.R. Reed (ankle/hamstring). Both players are considered questionable after failing to practice early in the week. Parker (14 tackles, 3.5 sacks) is tied for seventh in the NFC in sacks.

FANTASY FOCUS

The first thing that jumps out is McNabb's past success versus the 49ers. The veteran quarterback, who has been a solid fantasy start this year, has thrown for 638 yards with seven touchdown passes and zero interceptions in his last two versus San Francisco, including a career-high tying five scoring passes in a 2005 meeting. Westbrook owners will have to watch the inactive list on Sunday, but a betting man's guess says he doesn't play this weekend and Westy owners need to adjust accordingly. The Philadelphia D is also a great start, as the club will get to O'Sullivan a lot and Jackson's punt return touchdown last week ups the Eagles' defense/special teams value as well. Assuming a groin ailment doesn't slow him, Brown posted the first 100- yard receiving game of his career in his last meeting with the Niners.

Gore is a must-start, though if San Francisco falls behind early -- which is possible -- he will lose chances to rack up ground yards. Luckily, he is a big factor in the passing game as well. Odds are that San Francisco is going to have to throw a lot in this test, upping Bruce, Johnson and Arnaz Battle's value as receivers. O'Sullivan, though, might be forced into a lot of turnovers and sacks, meaning he is a risky start. Davis has become a non- factor and is hardly worth a roster spot at this point, while the defense isn't a solid play this weekend either.

OVERALL ANALYSIS

Both teams enter this test with 2-3 records, but the urgency is more apparent for the Eagles. While San Francisco is just a game behind first-place Arizona in the NFC West, Philadelphia has a pair of 4-1 teams ahead of it in addition to the first-place 4-0 New York Giants. While it is too early to call a Week 6 game a must-win, this is close enough for the Eagles. Luckily for them, they match up well with the Niners. A swarming Philadelphia defense will reek havoc on the embattled San Francisco line, and the Birds should get plenty of opportunities to work on their red-zone offense, with or without Westbrook.

Sports Network Predicted Outcome: Eagles 31, 49ers 13