INDIANAPOLIS — Robert Mathis likely won’t get a chance to defend his NFL sacks title.

Less than two weeks after starting a four-game, league-imposed suspension, the Colts’ best pass rusher sustained an Achilles tendon injury while working out in Atlanta.

A person with knowledge of the injury said Monday that Mathis tore the tendon, which would keep him out the entire season.

Coach Chuck Pagano said he would not speculate on the severity of the injury or how much time Mathis could miss until team doctors examine Mathis on Tuesday.

“We knew we were going to be without Robert for the first four games, but this is really a devastating blow for Robert and his family and this organization,” Pagano said.

The injury occurred while Mathis was away from the team, serving his suspension.

League rules prohibit Mathis from working out at the team complex or communicating with those inside the organization during his absence, so the Colts sent Mathis home with a workout regimen.

On Monday, Mathis contacted trainer Dave Hammer to inform the team that he had injured the Achilles and had already been seen by one doctor.

Bills

AT LEAST THREE GROUPS AIMING FOR BILLS: At least three ownership groups, including Buffalo Sabres owners Terry and Kim Pegula, submitted formal bids to buy the Buffalo Bills. A candidate could be identified by the end of the week.

Four people familiar with discussions revealed that information to The Associated Press. They spoke on the condition of anonymity because the sale is being conducted privately.

The other groups submitting bids were led by New York City real estate mogul Donald Trump and a Toronto group led by rocker Jon Bon Jovi. The bids were submitted to Morgan Stanley, the banking firm overseeing the sale process on behalf of late owner Ralph Wilson’s estate.

Chiefs

JOHNSON, DeVITO OUT FOR YEAR: Pro Bowl linebacker Derrick Johnson and starting defensive tackle Mike DeVito will miss the rest of the Chiefs’ season after MRI exams confirmed that both players ruptured their right Achilles tendons in Sunday’s loss to Tennessee.

Johnson went down without getting touched near the end of the first half. Eight plays later, early in the second half, DeVito went down at nearly the same spot on the field.

The blows are significant to a Chiefs team that was already missing several key pieces to injuries and suspensions, and was routed 26-10 by the Titans at Arrowhead Stadium. Johnson had four tackles before getting carted off the field, moving him within 15 of 1,000 for his career. That would surpass Gary Spani for the franchise record.

Rams

FISHER CALLS QB DRAMA ABSURD: Jeff Fisher referred to “absurd” speculation that he yanked quarterback Shaun Hill at halftime of the Rams’ opening blowout loss to Minnesota.

Fisher reiterated that the 34-year-old Hill is his starter and if healthy will get the call next week at Tampa Bay. He said Hill was day-to-day with a quadriceps injury and added he’s never played games with quarterbacks, and that Hill was “clearly ahead” of untested Austin Davis.

Hill made his first start since 2010, inheriting the job after Sam Bradford’s second season-ending left knee injury in nine months.

Around the league

Wide receiver Odell Beckham Jr., the former LSU standout, was inactive for the New York Giants’ season opener Monday night at Detroit with a hamstring injury. ... Running back LaMichael James was released by the 49ers. James had sought a greater role in the running game, but he had just two carries for 0 yards in Sunday’s victory against the Cowboys. ... Titans linebacker Zach Brown has a torn pectoral muscle, potentially a season-ending injury. ... Redskins nose tackle Barry Cofield (high ankle sprain) and tight end Jordan Reed (strained hamstring) could be sidelined for multiple weeks with injuries from the season opening loss to the Texans. ... The Vikings released safety Jamarca Sanford. ... With Dave Zastudil nursing a sore left groin, the Cardinals signed punter Drew Butler.