San Francisco 49ers

49ers CB Kenneth Acker was playing with fractured foot

Rookie 49ers cornerback Kenneth Acker said he played during the preseason with a stress fracture in his left foot, the reason he landed on injured reserve on cut-down day Saturday.

Acker, a sixth-round pick out of SMU, said the diagnosis was revealed to him on Friday after an MRI. “They were like, ‘You know you were playing the last two games with a stress fracture in your foot?’ ” Acker said. “I was like, ‘No, I didn’t know that.’ It’s not as severe as some others are where you have to get surgery or anything.”

Acker said he recalls feeling soreness in his foot at various points during the preseason but didn’t realize there was a fracture.

“Like anybody – if you play a game and come off the field, your foot’s going to hurt,” he said. “As a player, if you don’t see swelling or see any of those signs, you’re like, ‘I’ll just take a couple of days rest and come back and get better.’ ”

The injury makes Acker’s preseason all the more impressive. He began to assert himself in practices toward the end of training camp, then looked good in the preseason, especially during the second game against Denver. He had a sequence in which he drew an offensive penalty, knocked away a pass and came up with an interception, though the turnover was called back because of a 49ers penalty.

Had he not been injured, it’s likely he’d have made the 49ers’ 53-man roster – or another team’s.

“I’ll be better next year,” he said.