BALTIMORE -- Red Sox knuckleballer Tim Wakefield passed a vital test on Friday -- throwing a 40-pitch side session. By getting through it without a hitch, Wakefield is now likely to return to the rotation Monday night against the Royals for what would be just his third start since the All-Star break.

Wakefield was asked if he is now a go for Monday.

"In my mind, yes," said the veteran right-hander.

The Red Sox seem to be on the same wavelength, provided Wakefield passes a strength test on Saturday. Wakefield has a loose fragment in his lower back that has caused a strength deficit between his right and left legs.

"The idea will be to check in tomorrow, do some strength testing, but with the idea that he would pitch Monday in Kansas City," said Red Sox manager Terry Francona.

Not only does Wakefield give the Red Sox a quality starter by returning to the mix, but he would also give Francona the flexibility to get his other five starters an extra day of rest before their next turns in the rotation.

In particular, Francona is looking to get ace Josh Beckett an extra day. Presuming Wakefield pitches Monday, Paul Byrd would go on Tuesday, followed by Beckett and Clay Buchholz to wrap up the four-game series in Kansas City.

In recent years, the Red Sox have been big believers in getting their starting pitchers some extra rest late in the season.

Beckett is sixth in the American League in pitches thrown, with 3,166. Jon Lester is seventh with 3,136.

"We've had a lot of conversations, with especially [Beckett] and Lester, because they've carried a big load. When we all feel like it's in their best interest, I think we try to do it," Francona said. "I just think it's a really good time to give [Beckett] another day."

Because of Wakefield's back condition, the Red Sox don't expect the right-hander to pitch every five days. In fact, Wakefield would likely get another prolonged break following the Kansas City start, perhaps lining him up to pitch again during the season's final homestand. Wakefield made his first start after coming back from the disabled list on Aug. 26, and pitched again on Sept. 5.

When the Red Sox play a three-game series at Yankee Stadium next weekend, they will likely start Lester, Daisuke Matsuzaka and Byrd.