Los Angeles Rams running back Cam Akers is out indefinitely after tearing his Achilles tendon in an offseason training session.

The Rams confirmed the injury Tuesday, one week before veterans report to training camp.

Akers was expected to be the Rams’ starter in the backfield after coming on late in his outstanding rookie season. Akers had 272 yards from scrimmage in the Rams’ two playoff games, capping his rookie year with some of his best play.

The injury is a blow to Rams coach Sean McVay’s plans to build an elite NFL offense around quarterback Matthew Stafford, who was acquired in a blockbuster trade with Detroit for Jared Goff early in the offseason.

Akers intended to play a primary role as an every-down back for the Rams after sharing carries as a rookie last year with Darrell Henderson and Malcolm Brown in the team’s first season following Todd Gurley’s departure.

Akers got 14 carries in his NFL debut, but didn’t get that many touches again until December. The Florida State product took over the primary ball-carrying role for four of Los Angeles’ final five regular season games, averaging 3.95 yards on 86 carries — including a career-high 171 yards against New England.

Akers’ athleticism and explosiveness made him the clear top choice heading into the playoffs, where he rushed for 131 yards and a touchdown in the Rams’ victory at Seattle. He added 91 yards and a touchdown in Los Angeles’ season-ending loss at Green Bay.

“It’s been in Ohio as early as the mid-1850s at least, brought in as an ornamental plant because of its unique foliage and white flowers,” Gardner said. “It was actually planted in people’s landscaping, and it has been spreading.”

Henderson is still with the Rams, while Brown left for Miami. Los Angeles also has Raymond Calais and Xavier Jones, who both have limited NFL experience, along with rookie seventh-round pick Jake Funk.

The Rams’ veterans will report to UC Irvine on Tuesday, July 27, with their first practice the next day.

The NFL Network first reported Akers’ injury.