Kiko Alonso, the Philadelphia Eagle's linebacker, left last Sunday's match against the Dallas Cowboys with an apparent left knee injury. It is unclear what exactly happened but the team announced that he would not return to the game.

The Eagles acquired Alonso in the offseason, hoping that he would add some speed to the team's defense. However, that plan may be put on hold as the player's test results on Monday could reportedly place him on the injured reserve list and put his entire season "in jeopardy," according to Mike Garafolo of Fox Sports.

On Sunday, the 25-year-old linebacker left the Eagles' 20-10 loss to the Cowboys during the second quarter. He sustained an injury to his left knee which was already surgically repaired in July following an early end to his 2014-15 season. This time, he has sprained his ACL, a ligament located in the knee joint, and is talking to doctors regarding his options.

"Kiko is still in the evaluation process. We're crossing our fingers and hoping everything turns out for the best. For this week, I don't expect him to play," defensive coordinator Bill Davis told ESPN on Tuesday.

Aside from Alonso, fellow linebacker Mychal Kendricks also injured his hamstring muscles during the same game, making the Eagles extremely thin in the middle. With Alonso and Kendricks out, rooking linebacker Jordan Hicks was able to play a significant amount of time against the Cowboys on Sunday.

"Jordan did a nice job stepping in. He's a very mature rookie. He went out there, and it was not too big for him. He played some real good football for us," Davis mentioned.

The Eagles plans to put considerable depth at the inside linebacker position with the return of DeMeco Ryans, who has just recovered from a torn Achilles tendon. If Alonso really ended up on injured reserve, it will mean that an increased load will be put on veteran Ryans' shoulders.

In the offseason, coach and de facto general manager Chip Kelly acquired Kiko Alonso in a trade that reportedly put him on the hot seat. He traded All-Pro running back LeSean McCoy to the Buffalo Bills in return for Alonso and his questionable knee injury.

Nevertheless, Alonso has been one of the best linebackers in the NFL when healthy, or when he was in his rookie season in Buffalo to day the least. After making him a second-round pick in the 2013 Draft, he delivered 159 tackles, a forced fumble, two quarterback sacks, and four interceptions while playing in all 16 games.