The Philadelphia Eagles placed running back Jay Ajayi on injured reserve Monday, shortly before several outlets reported the running back has a torn anterior cruciate ligament.It’s unclear which knee Ajayi injured or when it occurred, but the team’s website said it happened during Sunday’s loss to the Minnesota Vikings.Ajayi had eight carries for 29 yards and a lost fumble, along with one catch for 5 yards while playing 29 snaps (49 percent) against Minnesota. His last touch was a 6-yard grab early in the fourth quarter that was called back by penalty, but he appeared normal after the play. He ran a route from the backfield on the next play, his final snap of the day, with no apparent issue.Ajayi, 25, tore the ACL in his right knee in 2011 while at Boise State and slipped to the fifth round of the 2015 draft amid concerns about a chronic condition in the knee. The Miami Dolphins gave Ajayi regular rest during his time with the team before trading him to the Eagles last season for a fourth-round pick.Ajayi sustained a transverse process fracture in his back this season, missing much of Week 2 and all of Week 3 before playing through it the last two weeks. He finished the season with 45 carries for 184 yards (4.1 average) and three scores, along with five grabs for 20 yards.In the final year of his contract, Ajayi has 2,516 career rushing yards (4.5 average) and 13 touchdowns across four seasons.Ajayi was critical after Sunday’s loss of the lack of running plays against the Vikings, as the Eagles finished with 35 pass plays against 17 runs despite averaging 4.8 yards per carry.