COSTA MESA, Calif. -- Coming out of a bye week, the Los Angeles Chargers hoped for continued recovery to their injury-plagued roster, but that does not appear to be the case for wide receiver Keenan Allen.

Allen expressed frustration Wednesday over yet another setback in his recovery from a left hamstring injury, which puts into question his status ahead of a Week 9 matchup against the Atlanta Falcons.

After sitting out five games following the season opener, Allen returned to the lineup in a Week 7 loss to the Seattle Seahawks. On a pitch count, he played only in the first half and caught two passes for 11 yards.

Allen said he "felt great" in the game, but clarified that he was not 100 percent.

"Nothing happened in the game," Allen said of the injury when asked how he suffered the setback. "Taking my time with it and just going through it how we planned it and just through the bye week, kind of hit it again.

"I don't think it was a restrain or anything. It is just some more scar tissue that is trying to break off and whenever it is ready to heal, just got to let it do its own thing."

Allen, 30, did not practice Monday or Wednesday, saying he felt only decent and was certainly "worse" than before the bye week.

If Allen is unable to play against the Falcons, the Chargers will be without their top three receivers. Mike Williams already has been ruled out because of a right high ankle sprain and coach Brandon Staley said wide receiver Joshua Palmer has cleared concussion protocol, but would not commit to his return on Sunday.

The Bolts also have wide receivers DeAndre Carter, Michael Bandy and Jason Moore Jr. on the roster.

Allen did not provide a timetable for his return, but said that he did not want to come back until there was absolute certainty in his health.

"I definitely don't want to do the halfway thing again," said Allen, who has caught six passes for 77 yards in two games this season. "Just want to come back 100 percent and not worried about it."

The Chargers are 4-3 and one game out of first place in the AFC West behind the 5-2 Kansas City Chiefs.