CLEVELAND, JUNE 19 -- Baltimore Orioles outfielder Phil Bradley will have arthroscopic surgery Friday to repair torn cartilage in his left wrist and may be out for the season.

The amount of time he will miss will not be known until Hugh Baugher, a hand specialist, performs the operation. Bradley said tonight in a telephone interview: "I've been told from the get-go six weeks with the simplest repair, three months if it needs a lot of work."

Bradley was placed on the 21-day disabled list, but Manager Frank Robinson said his spot on the roster was vacant for tonight's game against the Cleveland Indians because Orioles officials received the diagnosis too late in the day to make a move. The club announced Monday that Bradley would not be making this road trip, which includes three-game series here and in Boston, because of a back injury he sustained Saturday.

If the Orioles turn to Class AAA Rochester for a replacement, it seems likely they will recall outfielder Donell Nixon or Jeff McKnight, a switch hitter who plays outfield and infield.

"We will make a determination after the game and have somebody up here tomorrow," said Robinson, whose club is down to four outfielders because Brady Anderson is on the disabled list with a sprained ankle.

Nixon, who was signed as a minor league free agent in April, has more than three years of major league experienece, most recently with the San Francisco Giants. Going into tonight's game, he was batting .264 in 29 games with three triples, two home runs and three stolen bases in six attempts.

McKnight, signed last winter as a six-year minor league free agent from the Mets, has played in six major league games. He was batting .246 in 46 games with seven doubles, three homers and 24 RBI.

The Orioles also could opt for a free agent signing or a trade. But Anderson, placed on the 15-day disabled list June 9, should be ready in about a week.

Bradley, whose wrist has been bothering him since late last season, had a cortisone shot about 3 1/2 weeks ago. Apparently, that brought him only temporary relief. He had a magnetic resonance imagery (MRI) examination last week, and that revealed the cartilage damage.

"I was relieved," said Bradley, who has been on the disabled list only one other time in his seven-year career -- in 1986, when he missed about two weeks with a stress fracture in his left foot when he played for Seattle. "It was not something that just happened recently. It's been there and it was not going away."

Mitchell Gets Another Start

John Mitchell will be the Orioles' starting pitcher here Thursday night, Robinson said. On Saturday, in his first start since being recalled from Rochester, Mitchell allowed the Red Sox five runs on eight hits and three walks in 5 1/3 innings. He threw 88 pitches, 40 for balls.

"I'm glad it wasn't just a one-game deal," said Mitchell, who was 5-0 with Rochester. "It's just a matter of me throwing strikes."