Indianapolis (AP) — Anthony Gonzalez may be out longer than the Colts first feared and they appear to have a replacement for him, too.

Coach Jim Caldwell said the third-year receiver could miss up to two months after spraining ligaments in his right knee during Sunday's 14-12 victory over Jacksonville.

Indy has signed former Philadelphia receiver Hank Baskett to take Gonzalez's place, and three-time league MVP Peyton Manning hopes he can find his way around the offense fast. The team made the announcement following Thursday's practice.

"Hopefully we can catch him up as soon as possible," Manning said. "It's a lot of offense to learn in a couple of days but he's a veteran, so he could help us."

The Colts play Miami on Monday night.

Team president Bill Polian said this past Monday that the Colts would only sign a veteran receiver if Gonzalez was expected to miss more than four weeks. The next day, in an interview on NFL Network, Polian acknowledged Gonzalez was going to get a second opinion on the injured knee.

Caldwell did not provide any new details about the injury Thursday other than to say: "It could be two to between six and eight weeks."

Initial reports indicated Gonzalez would not miss more than six weeks.

Losing Gonzalez for an extended period is a big blow to the Colts, who expected their 2007 first-round draft pick to replace Marvin Harrison, the franchise's career receiving leader, in the starting lineup this season. Harrison was released in a cost-cutting move in February and remains a free agent.

Gonzalez and Harrison put up nearly identical numbers last season, and the Colts thought Gonzalez was headed for a breakout year until he stepped across the line of scrimmage late in the first quarter Sunday and crumpled to the ground without touching another player.

The injury left the Colts (1-0) thin at receiver. Aside from Reggie Wayne, the only other healthy receivers on the roster are second-year pro Pierre Garcon and rookie Austin Collie, a fourth-round draft pick from Brigham Young.

Both put in extra time in the film room this week.

"Pierre is going to be a big part of our game plan, Austin Collie, too, no question," Manning said. "But this is the NFL. You can't just draw up a play and say this ball has got to go to Dallas Clark. Pierre has worked hard over here, I think he spent six hours over the last two days studying film and Austin has done that as well."

Collie already has learned one significant difference between college ball and the NFL.

"I didn't feel as prepared for Jacksonville as I should have been," he said. "I think I underestimated what needs to be put into it, and I think I learned that lesson. I'm getting in the film room more, seeing how they disguise different coverages and different blitzes."

Baskett gives the Colts some intriguing possibilities. At 6-foot-4, 220 pounds, he's bigger than any other Indy receiver.

He spent all three of his previous NFL seasons with the Eagles, who reached the NFC championship game last season. But Baskett has just 72 career receptions for 1,052 yards and six TDs, and he caught only one pass for 6 yards in Sunday's rout of Carolina.

"It's definitely going to be a crash course," Baskett said after practice. "Everybody talked about Philadelphia's offense. That was a lot to learn. But coming in (to Indianapolis) during the season and getting here, there's definitely a lot to learn. Peyton and the guys stayed out there with me to throw a couple routes and just work me in. I'm definitely up to the challenge."

The Eagles released Baskett on Wednesday.