The Indianapolis Colts lost the services of wide receiver Anthony Gonzalez late in the first quarter of today’s game with Jacksonville in Lucas Oil Stadium.

Gonzalez went down to the turf without being touched while running back Donald Brown was running for a 1-yard gain. Gonzalez had to be helped off the field after injuring his right knee.

Colts coach Jim Caldwell said he had no idea about the severity of Gonzales’ injury or how long it might keep him out, but NFL.com reported that the former Ohio State standout strained a knee ligament and could be out two to six weeks.

The reaction from Colts quarterback Peyton Manning could be sign about the seriousness of the injury. Gonzalez, drafted in the first round in 2007, was poised to play a more significant role after the offseason release of Marivin Harrison, the franchise’s all-time leading receiver.

“I’m sick about Gonzalez, whatever his injury is going to be,” Manning said in a USA Today blog posted late this afternoon by Sean Leahy. "I didn’t see it, but I actually asked (Jacksonville cornerback Rashean) Mathis, ‘What happened?’

“He said, ‘I didn’t even touch him. He went down.’ I’ve got a sick feeling about that. He’s worked so hard this offseason. I certainly hope it’s not a season-ending injury. I hope he’s back soon. He’s a big part of our offense. … We need him back. For us to be the type of team that we want to be, we’re going to need Anthony Gonzalez back.”

Rookie Austin Collie replaced Gonzalez in the lineup.