WESTMINSTER -- Baltimore Ravens offensive tackle Jared Gaither is down to 311 pounds, and the organization wants to know why.

Gaither hasn't practiced since Friday morning. That afternoon, he was carted off the field with a lower back injury that the team characterized as cramps.

Gaither is also dealing with back spasms and other ailments.

“I’d like to be able to tell you what it is,” Ravens coach John Harbaugh said. “I don’t know. He’s getting bloodwork, and they say they’re going to do some tests on him on Monday, and they’ll tell us what it is. That’s all they’ve told me.”

Harbaugh seemed annoyed that the 6-foot-9 tackle has gotten so light after playing at 340 pounds last season and resembled a basketball player more than an NFL offensive lineman.

Gaither didn't work out under the supervision of the team.

“He made a decision,” Harbaugh said. “He was working out on his own, so it’s not like he was around. He made the decision to go lighter. I can’t even explain to you why.”

With Oniel Cousins on the physically unable to perform list after throat surgery, Tony Moll injured and Stefan Rodgers suffering from knee and ankle issues, former college basketball player Joe Reitz lined up at right tackle with Michael Oher shifting to the right side.

The Ravens also had rookie Ramon Harewood play right tackle, too.

The Ravens signed offensive guard Daniel Sanders and cut undrafted rookie wide receiver Rodelin Anthony.

“The biggest problem is that we’re short on numbers,” Harbaugh said. “And Dan’s a guy who was with us all through the offseason. So he knows how we work, he knows the offense, he’s in shape. So we felt like part of the plan was to have guys that we could bring back if we needed to, and obviously on the offensive line, we needed to do that.”

Oher said he has spoken with Gaither and expressed confidence that he'll be fine.

"He's doing great," Oher said. "He's going to be here for us. He's a great player. We need him. He's all for the team. You just got to watch things close."