Raiders RB Jalen Richard injures calf in practice

NAPA, Calif. — Jalen Richard suffered a setback Sunday in his roster-spot bid.

How significant of one was not immediately clear.

The Raiders running back exited midway into practice and was diagnosed with a left calf strain, a source said. Richard is vying to make the club in a crowded backfield. It’s possible, if not likely, the team will sign a running back soon, given rookie running back Chris Warren is nursing an injury, too.

Oakland currently has a vacancy on its 90-man roster, and Warren did not practice Sunday with his unspecified ailment.

The timetable on a calf sprain can vary based on its degree. An MRI is a common tool to determine the severity. Richard was seen walking after practice without crutches or a protective boot, an encouraging sign that he may have avoided the most serious variety. Even minor calf strains, though, are tempermental and prone to aggravation.

Richard, 24, seems unlikely to practice Monday afternoon. The Raiders will have their first off-day of training camp Tuesday.

The third-year veteran entered the league as an undrafted rookie from Southern Mississippi. He earned a roster spot in camp and made a quick impact, the first regular-season carry of his NFL career was a 75-yard touchdown against the New Orleans Saints. That run was no blip; he averaged 5.1 yards on his other 82 runs in 2016. Last year, he averaged 4.9 yards on 56 totes while catching 27 passes for a career-high 256 yards.

His special-teams performance, however, dropped off a bit.

Richard struggled with ball security as a returner. Since the spring, his reps under new special teams coordinator Rich Bisaccia suggest he’s not in serious contention to return punts in 2018. Wide receiver Ryan Switzer, wide receiver Dwayne Harris, cornerback Nick Nelson and wide receiver Griff Whalen handled those reps Sunday before Richard exited.

The Raiders are expected to carry at least four running backs on their 53-man roster. Those include Marshawn Lynch and Doug Martin, who project to share much of the load, and fullback Keith Smith, who is a roster lock. DeAndre Washington and Richard seek to demonstrate their value to a new coaching staff.

For Richard, that just became more difficult.

Notable

■ After switching from outside linebacker to defensive end, Bruce Irvin said Sunday that he’s eager to be in pass coverage less often in 2018. The interception he returned Friday for a touchdown did not change his opinion. “I’d rather have a sack over a pick-six any day,” he said.

■ About 1,100 spectators, most of whom are season ticket holders, attended Sunday’s invite-only practice.

Contact reporter Michael Gehlken at mgehlken@reviewjournal.com. Follow @GehlkenNFL on Twitter.