Ideally, backup quarterback Graham Harrell would have improved on the two touchdown drives he led in the preseason opener in San Diego.

Instead, Harrell led the No. 2 offense to just three points Thursday night against Cleveland, but Head Coach Mike McCarthy defended Harrell’s play a bit after grading the film.

“I would say Graham probably graded out higher than the perception of how people felt that he played,” McCarthy told reporters on Friday. “There are some throws that he missed.

“He’s growing. He’s getting a full dose of what it’s like to play when more things go wrong, unfortunately, than normal. We need to do a better job as an offense, and he will do a better job leading us.”

Harrell finished 12 of 24 passing for 100 yards with two interceptions in playing most of the final three quarters. McCarthy certainly didn’t fault Harrell on either interception. The first was a Hail Mary on which he couldn’t set his feet because of pressure from the back side and on the second, tight end Ryan Taylor fell down as he broke back to the ball.

“I gave him an accurate throw on that particular play,” McCarthy said of the second interception, which was run back for a touchdown by Cleveland’s David Sims.

The head coach also suggested Harrell didn’t get the kind of support from his offensive mates that leads to success. McCarthy was critical of the No. 2 offensive line, which struggled against Cleveland’s first-string defense in the second quarter and didn’t fare much better as the game progressed. Two of the five first downs Harrell produced came on scrambles when he was forced from the pocket.

McCarthy’s comments could signal changes heading into the third preseason game.

“The second offensive line needs to play better,” McCarthy said. “It did not grade out very well. I thought the first group graded out very well, but that was not the case with the second group.

“You talk about opportunity, there’s a lot of opportunity there. There are jobs to be won.”

McCarthy was pleased with the work on special teams. The coverage units allowed just nine yards on three punt returns, and only one of three kickoff returns was longer than 22 yards.

Linebacker Robert Francois recorded three coverage tackles, while rookies Casey Hayward, Sean Richardson and Otis Merrill had one apiece. Merrill also broke free for a 60-yard kickoff return late in the second quarter.

“First of all, how they’re flying around,” McCarthy said when asked what he liked about the special teams play. “We’ve got some young guys who have really improved from year one to year two. I like the rookies, they’ve picked it up there.”

Injury update: Linebacker Desmond Bishop had surgery on his hamstring Friday morning and was “doing well,” McCarthy said. No final decision has been made on Bishop’s status for the season.

Receiver Greg Jennings has advanced far enough in the concussion protocol that he “potentially” could practice on Sunday. Tight end Jermichael Finley (quad) is also “getting close.”

At the most depleted position, running back, newcomer Cedric Benson will practice for the first time in pads on Sunday. Fullback John Kuhn (ankle) might return to the field sometime this week, but Brandon Saine (hamstring) could be another week away.