Already missing their starting quarterback, the Chicago Bears lost their running back Sunday.

Matt Forte walked gingerly into the tunnel with a sprained right knee in the first quarter of a 10-3 loss to Kansas City.

“It’s not a good feeling when you see your star tailback go down with a knee injury,” coach Lovie Smith said. “Part of the game. We’ll just keep our fingers crossed and hopefully it’s not that serious.”

Jay Cutler broke his thumb two weeks ago. Forte, third in the NFL in rushing entering the game, took a hit to the right knee from Derrick Johnson on a run for no gain deep in Chicago territory with 6 minutes left in the first period.

In his second game back from a right hamstring injury, Houston Texans All-Pro receiver Andre Johnson hurt his left hamstring.

Johnson left in the third quarter of a 17-10 win over Atlanta. He injured his right hamstring in Week 4, underwent minor surgery and sat out six games.