The one thing that makes Sunday’s AFC wild-card round game between Baltimore and New England stand out from the other three playoff games is that Ravens-Pats is the only matchup of the four that wasn’t also played in Week 17 – New England is a 3.5-point favorite on Bodog.

But that’s not to say these teams don’t know each other. In Week 4, also in Foxboro, the Pats beat the Ravens, 27-21. But that score might be a bit misleading. Baltimore had more rushing yards and more passing yards than New England. Plus Pats QB Tom Brady was just 1-for-4 for 11 yards on third downs in the game – New England converted just four third downs overall. But the Patriots won in large part because Ravens WR Mark Clayton dropped a late fourth-down pass, while it also helped that the Pats dominated time of possession and Baltimore committed one more turnover than New England and had nine penalties, including two roughing-the-passer calls.

Of course, the Patriots had star WR Wes Welker in that game, although he had just returned from a two-game absence due to injury. Welker wasn’t a huge factor against Baltimore with six catches for 48 yards, although he was targeted 10 times by Brady. The Pats won’t have Welker this time around or at all this postseason after he tore ligaments in his knee in the regular-season finale against Houston.

And some would argue that Welker is the second-most important player on the team behind Brady. How important? Well, he led the league in catches despite missing basically three games, and Brady’s completion percentage with Welker in the lineup is more than 11 points higher this season (68) than it is without him (56.3). With Welker on the field, Brady averaged 8.3 yards per pass, and without him only 5.9 yards.

Welker simply opens up both the deep throws to Randy Moss and the running game by being Brady’s security blanket and being able to make yards after the catch. Rookie Julian Edelman had a nice game when Welker went out very early against the Texans, but it’s unrealistic to expect anything approaching Welker’s numbers in the playoffs.

New England has never lost to Baltimore in five meetings (this is the first in the playoffs), and the Pats have won 23 straight games at home when Brady has started – they were the only home unbeaten team this season (5-3 ATS) and averaged better than 31 points there.

There are only two teams in the playoff with losing road records this season, and they are both in this game. The good news for Baltimore (3-5 on the road, 3-4-1 ATS) is that it enters off a road win over Oakland. The bad news is that the Ravens’ only two road wins since Week 2 are against the lousy Raiders and Browns. And that Week 2 road win in San Diego was well before the notoriously slow-starting Chargers got their heads on straight. In fact, if you throw out that San Diego victory, Baltimore’s eight wins came against teams with a combined record of 45-83.

Ray Rice figures to be the key to Baltimore’s offense. In that first meeting, he had 152 total yards on 16 touches but didn’t score. The Ravens averaged 6.8 yards per carry in that Week 4 game, but the Pats also were without top linebacker Jerod Mayo, the team’s leading tackler. Rice is also the Ravens’ leading receiver with 78 catches. Obviously the Ravens need QB Joe Flacco on his game, but he struggled some in the final two games of the regular season. Look for the Pats to blitz him often.

The wild card in this game has to be Ravens safety Ed Reed, who probably won’t be 100 percent after missing four of the final five games of the season with a groin injury. He had two picks in the wild-card win over Miami last season, returning one for a TD – he has 13 career returns for TDs. As long as he doesn’t bring one back, New England should win a close game.

Baltimore seems to enjoy being the wild-card team, however. Last year the Ravens made it to the AFC title game as the No. 6 seed, and the Ravens won a game as the wild card in the 2001 season and, of course, took the Super Bowl as the wild card in the 2000 season. In the 2003 and 2006 seasons as the division champion, Baltimore lost its first playoff game.

The weather might favor the physical Ravens (and the Bodog under of 43), as it will be plenty cold (about 22 degrees) but it is supposed to be sunny.