Bills vs. Jaguars -- Week 13

Where: Orchard Park, N.Y. (turf, outdoors)

When: Sunday, 1 p.m., ET (CBS)

Spread: Bills by 6 

Forecast: 45-50 degrees, rain likely

Records: Bills (Overall: 4-7, AFC East: 1-3); Jaguars (Overall: 2-9, AFC South: 2-3)

Past results: Two most recent meetings -- Oct. 10, 2010: Jaguars 36, Bills 26; Nov. 22, 2009: Jaguars 18, Bills 15.

Series record: Tied, 5-5.

What matters: Buffalo’s improved defense and the two QBs -- Ryan Fitzpatrick and Chad Henne. Buffalo’s beleaguered defensive unit has made some major strides over the past two weeks. Is the defense for real, or did Buffalo benefit from playing two rookie quarterbacks (Ryan Tannehill and Andrew Luck)? DE Mario Williams has finally started to earn his $100 million paycheck and picked up three sacks against the Colts in Week 12. DE Kyle Moore, who has stepped up on the other side, has also impressed since entering the lineup due to injuries. The Bills could use a big game from those two against Henne, who has improved Jacksonville’s offense dramatically since taking over for Blaine Gabbert. Fitzpatrick has been up and down in recent weeks. He completed 51.5 percent of his passes for 180 yards, 1 TD and 1 INT in Buffalo’s 20-13 loss to Indianapolis on Sunday.

Who matters: Henne, Fitzpatrick, RB C.J. Spiller. As mentioned above, Henne has been the spark behind Jacksonville’s turnaround the past two weeks. He was sensational in a comeback effort against the Houston Texans in Week 11 (16 of 33, 354 yards, 4 TDs and no INTs) even though the Jaguars eventually fell 43-37 in overtime. He was strong once again in Week 12, helping the Jaguars post their second win of the year in a 24-19 victory over Tennessee (17 of 26, 261 yards, 2 TDs and 1 INT). If Henne keeps it up, the Bills may wish that they had the Jaguars on their schedule earlier in the year. Fitzpatrick needs to be more accurate in the pocket for the Bills. He missed on two potential big gains downfield to wide-open targets against the Colts and the Bills need him to be more accurate throwing the ball. Spiller has finally jumped ahead of veteran Fred Jackson on the depth chart, and deservedly so. Spiller’s been outstanding with the ball in his hands this season (830 yards, 4 TDs on 123 carries). His average of 6.75 yards per carry is the third-highest average by any NFL RB since 1960 among players with at least 110 attempts through 11 games.

Key matchups: Jaguars WRs Cecil Shorts and Justin Blackmon vs. Bills CBs Stephon Gilmore and Leodis McKelvin, Bills DE Mario Williams vs. Jaguars RT Cameron Bradfield, Jaguars LB Paul Posluszny vs. Bills RB C.J. Spiller. WR was an area of weakness for years in Jacksonville, but Shorts and Blackmon have helped the Jaguars make tremendous strides at that position. Shorts leads the team in receiving yards (747 yards, 6 TDs on 36 receptions) while the rookie Blackmon (548 yards, 3 TDs on 38 receptions) is also explosive and has come on strong as of late. Blackmon had 236 yards receiving and one TD against the Texans in Week 11. Both missed practiced due to injuries on Thursday, though (Shorts -- hamstring, Blackmon -- groin), which could be a concern for Jacksonville on Sunday. Gilmore and McKelvin have made strides in recent weeks. Williams has moved around a bit more the last few games, so he could see both Bradfield and LT Eugene Monroe. No matter who he’s up against, the Bills hope that he can maintain his hot streak. Posluszny (92 tackles) will want to put together a good performance against his former team. He’ll have a tough assignment in Spiller.

Injuries of note: WR Donald Jones (calf) is questionable after missing practice on Friday. If he’s unable to go, that could be a big blow to Buffalo’s offense given the Bills’ lack of depth at WR. Brad Smith and Ruvell Martin are next on the depth chart. CB Justin Rogers (foot) showed some improvement on Friday but is questionable. If he can’t handle his usual slot responsibilities, Leodis McKelvin would likely move inside. DE Mark Anderson (knee) and DE Chris Kelsay (neck) are out.

Inside stuff: The Bills have shot themselves in the foot in recent weeks inside the red zone. The Bills scored TDs on one of three red-zone attempts in Week 12 and were 0-for-4 against Miami in Week 11. “We have to avoid the negative plays,” Gailey said. “We get down there and we get a negative run, we get a missed assignment on a run or we don’t get the ball up in there ... it is several things that are keeping us from being as productive as we need to be in the red zone.”

Connections: Jaguars coach Mike Mularkey was head coach of the Bills from 2004-05. He was Buffalo’s coach during its last winning season (9-7 in 2004). Posluszny was a second-round pick of the Bills in 2007 and led the Bills in tackles from 2008-10.

Stat you should know: After a slow start to his Bills career, DE Mario Williams had three sacks in Week 12 and has five sacks since undergoing wrist surgery during Buffalo’s Week 8 bye.

Record watch: With a touchdown pass from Fitzpatrick to WR Stevie Johnson, the duo will become the fourth tandem in team history to connect on 22 or more touchdowns.

Looking ahead: If the Bills are able to beat the lowly Jaguars, they could go on a bit of a run to end the year. Their final four games are against St. Louis (4-6-1), Seattle (6-5), Miami (5-6) and the New York Jets (4-7). At 4-7, they appear to be all but out of the playoff race, but you never know -- especially when looking at the competition for the final wild card spot in the AFC.

Prediction: Bills 20, Jaguars 13

For more updates on the Bills, follow correspondent Mark Ludwiczak on Twitter @CBSBills and @MarkLud12.