Alameda, Calif. ? Right tackle Lincoln Kennedy’s torn left calf still aches, and he can’t play.

Right guard Mo Collins has an injured knee, and he can’t play.

To make matters worse for the beleaguered Oakland Raiders, left guard Frank Middleton went down because of a severely strained right quadriceps in Sunday’s loss at Cleveland. He might be sidelined for the season.

The pride of Oakland’s veteran offensive line is hurting, too.

The Raiders committed an NFL season-high 19 penalties in a demoralizing 13-7 loss to the Browns, and a good share of the infractions were by the offensive line.

In the past, this unit has handed down fines to each other as a motivational technique to avoid mental miscues, then used the money for a party after the season. If things don’t get better in a hurry, they won’t be feeling festive in January.

Oakland, 0-4 on the road for the first time since 1962, had five straight penalties for 35 yards during one offensive series in the third quarter. Three of those calls went against the offensive line, specifically the backups for the injured players.

Brad Badger, who replaced Collins, began the string of penalties with a false start. Then Langston Walker, filling in for Kennedy for the third straight week, was flagged for holding and tripping on consecutive plays.

“Spirits are down,” Kennedy said. “Where we falter mostly now is we honestly don’t know what we’re capable of. Unlike last year when we came out of the blocks and started 4-0, we showed signs of what we were capable of doing. It’s at a point where you’re in a slump like this, you’re very capable of being 0-6, and you’re very down on everything that you do. You question everything about it because nothing has gone right.”

Oakland coach Bill Callahan watches the scoreboard late in the Raiders' loss to the Browns. Oakland fell to 2-4 Sunday at Cleveland.

Of the healthy players, left tackle Barry Sims is the only offensive lineman who opened the season in the same position he’s playing now.

“We always look for the leadership of those guys and draw from their energy,” said Sims, in his fifth NFL season. “I look for their feedback when they come off the field. Not having them, it’s noticeable.”

Second-year coach Bill Callahan keeps saying he and his staff are working harder than ever to rectify all the problems — but when things actually will change is anybody’s guess.

The Raiders (2-4) have an extra day of practice this week, and the schedule doesn’t get any easier — their next game is a Monday-night showdown with unbeaten Kansas City.

“When you do create those penalties, it’s like a sore thumb sticking out there,” Callahan said.

Behind the strong play of their offensive line, the Raiders had the top-rated offense in the NFL last season on the way to winning the AFC title, but this year has been brutal.

Rich Gannon and company have been outscored 144-115, and it’s hard to believe this team won the AFC West and then the conference title.

Because of the injuries, many young players are being thrown into the mix because Oakland is out of options.