(973espn.com) - Chris Long was the hero against his original NFL team but the joy of an exciting 43-35 win over the Los Angeles Rams was mitigated by a potentially serious left knee injury to MVP candidate Carson Wentz.

Wentz, who threw for four touchdowns on the afternoon in less than three quarters of action, suffered the injury while diving for another score that was ultimately called back by a Lane Johnson holding penalty.

Rams' defenders Mark Barron and Morgan Fox sandwiched the second-year star as he was lunging for the end zone.

Wentz actually stayed in the contest for the remainder of the drive, which he finished with a fourth-down TD throw to Alshon Jeffery which put Philadelphia back on top of the see-saw and broke Sonny Jurgensen's single-season franchise record which has stood for 56 years.

Following the series, Wentz limped off and immediately went to the medical tent to be evaluated, and then walked off to the locker where he was quickly ruled out for the afternoon.

An NFL source confirmed to 973espn.com that the Eagles, who clinched the NFC East with the win, fear that Wentz has suffered a torn ACL.

Wentz finished 23-of-41 for 291 yards and a 100.8 passer rating, outdueling Rams QB Jared Goff, who was taken No. 1 overall in the 2016 draft, one spot ahead of Wentz.

"I don't know anything until we evaluate him [Monday]," Eagles coach Doug Pederson said.

Backup Nick Foles, a former starter for the Rams, finished by completing 6-of-10 passes for 42 yards, including a big third-down conversion late to Nelson Agholor.

The win, coupled with Minnesota's loss in Carolina earlier in the day, put the Eagles back on top of the entire NFC with an 11-2 record with three games to go in the regular season.

"Everyone is really excited about the win but you have your starting quarterback go down, it's emotional," Foles admitted. "It's emotional for me. I work with him every day."

10 THINGS YOU SHOULD KNOW:

-Wentz plays with a reckless abandon that makes him what he is as a player but if you get hit enough in this league, something is going to give. The Eagles' QB took a beating before the injury on Sunday and now the only hope is that the early concerns were overstated after an MRI. The speed in which Philadelphia ruled Wentz out is not a good sign.

-As the two best offensive teams in football, the Rams and Eagles were a combined 14-0 when they scored 30-plus points, Philadelphia is now 8-0 and the Rams 7-1.

-Left guard Stefen Wisniewski left with an ankle injury and was replaced by Chance Warmack before the Eagles ultimately went back to original starter Issac Seumalo. That position is obviously a concern moving forward but superstar Aaron Donald was held sackless so give the Eagles' offense credit for that.

-It wasn't the best day for Jim Schwartz's unit but they came up with some big plays when needed, most notably Long's strip sack that led to the FG that put Philadelphia up for good. The league's No. 1-ranked run defense could not handle Todd Gurley, however, who ran for 96 yards with two TDs on just 13 carries. In coverage, the issues were with shifty rookie Conner Kupp.

-Jay Ajayi may have seized the top spot in the Eagles' RB-by-committee, running for 78 yards on 15 carries, his most work to date since being picked up at the trade deadline from Miami.

-This was easily Torrey Smith's best game as an Eagles and his first 100-yard receiving game (6 for 100) since Sept. 20, 2015 at Pittsburgh when he was with the San Francisco 49ers.

-Zach Ertz was ruled out with the concussion he suffered in Seattle but Wentz is very close to Trey Burton on and off the field and that showed when he found his friend on two of his four TD passes on the day. Burton isn't the lengthy Ertz obviously but he creates his own mismatch issues with speed.

-Agholor continues to play at a high level, returning to his college stomping grounds to catch eight passed for 64 yards, not bigger than the late third-down conversion from Foles when he created just enough separation to make a lunging grab.

-If Foles is forced to take over as the starter as expected that means Nate Sudfeld is the new backup, something that gone have gone awry when Indianapolis wanted to sign the developmental prospect off the Eagles' practice squad earlier this season. Howie Roseman responded by offering a 53-man roster spot to the former Redskins' draft pick and now he's a play away from getting in.

-As far as Vegas goes, her's the impact of losing Wentz. Prior to Week 14, the Eagles were favorites (+200) to win the NFC and carried the second-lowest odds (+500) to win Super Bowl LII at BookMaker.eu. If Wentz suffered a season-ending knee injury as feared, oddsmakers u would adjust the Eagles’ chances to win the NFC to +400 and the Super Bowl to +1000. As far as the weekly odds for Philadelphia, there would be a 3- to 4-point dropoff in terms of value to the spread between Wentz and Foles.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen