INDIANAPOLIS — The injury list just keeps expanding for the Indianapolis Colts.

On Tuesday, two-time Pro Bowl cornerback Vontae Davis became the latest addition with what coach Chuck Pagano called a "pretty significant" groin injury that could keep him out of the regular-season opener and perhaps longer.

"He's week to week," Pagano said, divulging no other details including a timetable for Davis' return.

The nine-year veteran was injured during the first half of Saturday's game at Pittsburgh. He did not re-enter the game then missed Monday's practice to get a second medical opinion.

His absence only complicates the decision-making process for Indy's front office with the cut-down deadline looming with Saturday afternoon. Davis had arguably the best training camp of his career and was projected to be one of the defensive stalwarts following Robert Mathis' retirement. Davis missed the first two games last season with an injured ankle and six games in 2012 with a knee injury.

Indy must figure out what to do without Davis, their top defender, or Andrew Luck, their best overall player. Luck remains on the physically unable to perform list following off-season surgery on his throwing shoulder. He still has not practiced and if he stays on PUP following the cuts, Luck would miss the first six weeks.

Last month, general manager Chris Ballard told reporters he expected Luck to be active for the season opener — a prognosis that doesn't appear to have changed.

"We'll have that discussion in the coming days," Pagano said when asked if PUP was an option. "But I don't foresee that happening."

One possible solution could be two-time Pro Bowler Joe Haden, who is reportedly being shopped aggressively by the Cleveland Browns. Under different management, Indy and Cleveland have been trade partners before — most notably swapping Trent Richardson to Indy for a 2014 first-round draft pick that eventually resulted in the selection of Johnny Manziel.

Cleveland coach Hue Jackson did not deny the CSBSports.com report Tuesday.

But it's unclear if the Colts would be interested, if they have enough to pull off a deal or whether they want to take on Haden's $11.1 million salary cap number.

Indy already was expected to be without starting centre Ryan Kelly (foot surgery) until at least late September. No. 2 tight end Eric Swoope also is expected to miss multiple weeks after recently undergoing knee surgery, first-round draft pick Malik Hooker (shoulder) practiced in a red non-contact jersey Tuesday, left guard Jack Mewhort (knee) again rested and cornerback T.J. Green, a converted safety, is also dealing with a shoulder injury.

Add safety Clayton Geathers (neck), another starter, to the mix and the secondary is a mess. Geathers is expected to stay on PUP, and Green could be a candidate to go on the short-term injured reserve list, which would make him eligible to return later this season.

"It's deja vu," Pagano said, referring to Davis' injury. "You don't ever want to do it, you don't ever want to see a guy go down but that's why you have a 90-man roster."

Notes: The injury woes go well beyond the starters, too. Running back George Winn became the fourth player to go on injured reserve. To replace Winn, the Colts signed running back Daryl Richardson. ... Indy also waived tight end Steven Wroblewski and signed running back De'Mard Llorens.

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AP Sports Writer Tom Withers in Cleveland also contributed to this report.

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