KANSAS CITY, Mo. -- Wide receiver Jeremy Maclin underwent an MRI on Sunday for what the Kansas City Chiefs are calling a strained knee suffered in Saturday's 30-0 AFC wild-card win against the Texans.
A league source told ESPN's Ed Werder that the Chiefs are very concerned that Maclin may have suffered a significant ACL injury.
Maclin, who was in the Chiefs' locker room after the game but did not speak to the media, appeared to have the leg wrapped. He walked out of the locker room with a limp but without crutches.
On Sunday, Chiefs coach Andy Reid told reporters that he did not have an update on Maclin. Reid also said that Maclin is experiencing more pain in his ankle area than in his knee.
Kansas City quarterback Alex Smith told ESPN's Lisa Salters after the game that it would be a huge loss if the Chiefs had to move forward without Maclin.
"He's a huge player, tremendous player for us outside," Smith said. "It's hard. He's such a leader for us on and off the field."
Maclin, the Chiefs' leading receiver entering Saturday's game, left on a cart in tears after suffering the injury during the third quarter. He was replaced by rookie Chris Conley, who later caught a 9-yard touchdown pass on the same drive in which Maclin was injured.
Tight end Travis Kelce led all players with eight receptions for 128 yards.
Maclin had 87 catches for 1,088 yards and eight TDs in his first season with the Chiefs. The rest of the team's receivers combined for 84 receptions, 909 receiving yards and four touchdowns.
He has had problems with his right knee in the past.
Maclin tore his right ACL in Philadelphia Eagles training camp in 2013 and missed the season. He also suffered the same injury at Missouri four years before the Eagles drafted him in the first round in 2010.
Reid also said right guard Laurent Duvernay-Tardif suffered a concussion in Saturday's game.
ESPN's Ed Werder, Stats & Information and The Associated Press contributed to this report.