The look on CB Josh Victorian's face says it all about the Steelers' frustrating loss to San Diego on Sunday. (US Presswire)

Pittsburgh Steelers defensive end Brett Keisel said after Sunday's 34-24 loss to the Chargers that he sensed in the locker room that the team did not appear to be ready to play.

"You've got to be ready to go regardless of your opponent and regardless of their record,'' Keisel said.

Steelers coach Mike Tomlin, speaking Tuesday afternoon during his weekly press conference, agreed with that assessment.

"I don't mind a guy speaking the truth as he sees it,'' Tomlin said. "I'm a result-oriented guy, and the result of that performance would lead you to believe that was a possibility. So, I don't run away from that.

"The proof is in the pudding. I felt good about our preparation and overall game readiness, but our play didn't display that. So, I agree with him. We'll go back to the lab and work in an effort to put it on tape this week.''

Tomlin added that despite a lackluster first half where their offense began drives with poor field position, the Steelers responded pretty well and "were able to get back into the football game, particularly to end the half with points."

Any momentum a half-ending field goal provided, however,quickly diminished during the Chargers' monstrous 17-play, 78-yard scoring drive in 9:32.

The Steelers' disadvantage quickly ballooned to 27-3 when cornerback Quentin Jammer recovered what was ruled a lateral in the end zone for a Chargers touchdown, after they began the ensuing possession on the 8-yard line. The Steelers eventually got back in the game, 27-10, when Mike Wallace scored on a 40-yard bomb from Ben Roethlisberger, but Tomlin -- in retrospect -- still believed it wasn't prudent to go for a two-point conversion to lessen the deficit.

"I really kind of do feel the same way that I did (after the game),'' Tomlin noted. "The reason why I said that was I thought we had a better chance. And again, what we’re talking about are tough situations, but I thought we had a better chance to sneak back into the game if we didn't (go for two)."

Basically, Tomlin said he wanted the Chargers to run the ball so his team could stop them as opposed to San Diego passing it, which the Steelers had not stopped too often on third-down situations. Tomlin added that he was referring to the team's first touchdown and not the second one, which came with 6:07 remaining, because the game basically was out of reach at that point.

"It was bleak at that point,'' Tomlin said.

On the injury front, left offensive guard Willie Colon had surgery on his left knee Monday, and "he'll be out for several weeks,'' Tomlin said. He has not been ruled out for the rest of the season, but that likely is a foregone conclusion. Rookie No. 1 pick David DeCastro is expected to start at right guard, while Ramon Foster moves to left guard for the Steelers. And Maurkice Pouncey would stay at center. DeCastro has only been active for a few weeks after recovering from knee surgery in the preseason.

Offensive tackle Mike Adams (sprained ankle) and cornerback Ike Taylor (stress fracture in ankle) also are out this week. Taylor missed his first game in eight years, while Adams missed a second straight. With the time frame for Taylor's return still up in the air, the Steelers' cornerback situation is tenuous at best.

Second-year players Cortez Allen and Curtis Brown, who moved into starting and nickel roles, respectively, had a rough game against the Chargers. Tomlin said that Allen has a hip flexor injury that might "put his participation in question.'' The other starting corner, Keenan Lewis, also has a hip flexor that apparently is not as severe as Allen's.

That means first-year player Josh Victorian and Brown could get even more playing time than they have in recent weeks. Victorian was signed off the practice squad last Saturday and played extensively after Brown was torched during the second-half opening drive by the Chargers. Second-year player DeMarcus Van Dyke, signed Sept. 7 by the Steelers, also is in the mix.

"Obviously, we're running short at the cornerback position,'' Tomlin said. "Those guys who had an opportunity to step up and log a bunch of snaps over the last week and a half or so, it looks like that's going to continue. So, we'll continue to work with those guys and build a plan around what they're capable of executing and executing at a high level.''

Tomlin added that he did not anticipate changing the Steelers' running back situation with Jonathan Dwyer starting and Isaac Redman as the backup. That means former starter Rashard Mendenhall would be inactive for a third straight week. The Steelers dressed five wideouts this past week, but doing that again depends on the team's health at other positions, such as cornerback.

Lastly, OLB LaMarr Woodley is expected to return to practice this week after missing two games with an ankle injury, while QB Byron Leftwich is healthy and could be reinstated as the backup.

Follow Dale Grdnic on Twitter for real-time Steelers' updates @CBSSteelers.

Follow Steelers reporter Chuck Finder on Twitter @CBSSteelers and @cfinder.