GREEN BAY, Wis. -- Sure it’s only the backup quarterback -- and that caveat will stick as long as Aaron Rodgers stays upright -- but the Green Bay Packers haven’t found themselves scrambling at that position so close to the start of the regular season in years.

In the 5½ weeks since training camp opened, they have had four different No. 2 quarterbacks. It began with Graham Harrell, whose release on Aug. 24 gave way to Vince Young (who wasn’t signed until Aug. 5). B.J. Coleman had the job, albeit for only two days, after Young was released on Saturday. By Monday morning, Coleman was on the streets, and the Packers signed veteran backup Seneca Wallace.

“You go through that, you create opportunities, you evaluate and you assess,” Packers coach Mike McCarthy said Monday. “That’s really the matter of what happened. So if it didn’t work out the way people are used to, I make no apologies for that at all.”

Now, McCarthy and his coaches will have one week to prepare Wallace just in case he would have to play in the season opener at San Francisco on Sunday. They had nearly a month to get Young up to speed and that did not work out, but perhaps the process will be easier with Wallace, who has been a career backup.

“He clearly understands the role,” McCarthy said.

What’s more, the 33-year-old Wallace has vast experience in the West Coast offense that McCarthy’s system is rooted in. From 2003-09, Wallace played for the Seattle Seahawks under former Packers coach Mike Holmgren.

“It has a lot of carryover from the West Coast terminology that I’m used to,” Wallace said. “Mike Holmgren was here, and I was with him in Seattle for seven years. There’s a lot of carryover. Now it’s just trying to hone in, especially in this kind of week with the game coming up, and I just got here, trying to take in as much as I can.”

The Packers first expressed an interest in Wallace last season, when they brought him in for a workout in October. The former Iowa State standout was out of football all of last season after he was released by the Browns at the end of training camp. He signed with the New Orleans Saints this past April but was released midway through training camp. He then spent less than a week with the San Francisco 49ers before he left the team on the day of their preseason finale.

There’s no telling how well Wallace would be able to function if he had to play, especially early in the season, and there’s no guarantee he will turn out to be a better option than Harrell, Young or Coleman.

But when Wallace gets acclimated, he might be a valuable resource for Rodgers on the sideline during games and in the meeting room during the week.

“I think it’s been some years since they had a veteran quarterback backup to try to help A-Rod during the game and during the meetings and things like that,” Wallace said. “Just some of the insight that I can provide being around for a long time. I guess I’m the oldest one in the locker room [actually second oldest to Ryan Pickett], which is hilarious. It’s exciting just to be able to keep playing in this journey, and so I’m just excited to be here.”