OAKLAND -- The long-awaited return of Mariners southpaw James Paxton has been delayed again, this time by a torn fingernail on the middle finger of his pitching hand.

Paxton was removed from his third Minor League rehab start with Triple-A Tacoma on Wednesday in Salt Lake City, Utah, after throwing 44 pitches in what was expected to be his final tuneup before rejoining the Mariners' rotation after 3 1/2 months on the disabled list with a sprained tendon in the same finger.

"He's back in Seattle," Mariners trainer Rick Griffin said Friday. "We'll check him out when we get back there Monday. Then he'll play catch and do all that stuff. But the nail has to heal up."

Griffin said Paxton wouldn't be allowed to throw at all until Monday at the earliest and could be delayed further depending on what the doctor feels when he checks him out.

"It just depends on how it looks," Griffin said. "If he throws and pulls it back up, we're going to lose the three days. So we just have to see. The doctor will check it out Monday and we'll see if he's ready to throw."

Paxton has been sidelined since May 28 after injuring his finger in his 10th start of the season, but Griffin said the two issues are unrelated.

"The injury that he had originally, there's nothing wrong with that," Griffin said. "It's perfect. This is a new thing."

Paxton was throwing well in his third rehab outing, allowing five hits and two runs with two strikeouts before having to be pulled after his first pitch of the fourth inning.

The 26-year-old Canadian opened the season as Seattle's No. 2 starter and was 3-3 with a 3.70 ERA before his injury. He's 12-7 with a 3.05 ERA in 27 career starts, but missed four months last year with a strained lat muscle behind his left shoulder and has been sidelined for 13 weeks now this year with his finger issue.

Manager Lloyd McClendon had planned to slot Paxton back into the rotation during the Rangers series when Seattle returns home next week, but said Friday he's now not ready to reveal his pitching plans for that four-game set from Monday through Thursday.