The 6-foot-8 Alexander aggravated his right hamstring injury during rehabilitation exercises this week and is expected to be out from eight to 12 weeks, the team announced Thursday.

"I feel for Joe," Bucks coach Scott Skiles said. "He had a really good summer and worked hard. We felt like he was moving in the right direction. It's a big setback for him.

"We'll keep our fingers crossed that it won't be that long, that he can come back quicker than that."

Alexander was examined by Bucks orthopedic physician Michael Gordon and also received a second opinion from Green Bay Packers team physician Patrick McKenzie, according to Bucks officials.

The 22-year-old Alexander suffered the original injury during voluntary drills before training camp started in late September. The No. 8 overall pick in the 2008 draft, Alexander has been unable to take part in any practice sessions or games during the preseason.

Skiles said it would be hard to speculate on how Alexander could contribute to the team later this season. He plays at the small forward position, currently being shared by Carlos Delfino and Luc Richard Mbah a Moute.

"I think it depends on what's going on with our team at that time," Skiles said of a possible return in December or January. "If we're playing well, we're improving, and it appears we have some sort of rotation we like, if those things play out, it would be difficult for him.

"But Joe's not afraid of difficult. When he gets the green light to go, he'll come back working hard. We'll just have to see when that is and where we are as a team, and go from there."The Bucks have an Oct. 31 deadline to pick up the first option year, or third year on Alexander's rookie-scale contract. The option is for $2.76 million.

It is expected that general manager John Hammond will not make a decision on the option year until next week.

Alexander took the latest setback in stride, although he admitted it hasn't been easy to watch while his teammates have been working out during the preseason.

"There are times I'm very, very frustrated," Alexander said. "Overall the past five weeks have been frustrating."

Alexander said he aggravated his injury while running during a workout this week.

"The hamstring injury is a tricky one to come back from, because you have to constantly push to the limit," Alexander said.

"When you do that, there's a risk of re-injury, and that's what happened with me."

Jennings starts again: Skiles said rookie point guard Brandon Jennings will be in the starting lineup Friday night for the final preseason game against Detroit. The Bucks and Pistons will play in the annual MACC Fund Game at the Bradley Center.

It will be Jennings' third consecutive start, but it doesn't mean he's a lock to start the regular-season opener at Philadelphia on Oct. 30.

"I don't want to think too much about it now," Skiles said. "I want to see tomorrow night's game. After we get that under our belt, then we'll decide."

Veteran point guard Luke Ridnour also has played well in the preseason while averaging 7.4 points and 3.4 assists in 15.4 minutes. Jennings is averaging 11.6 points and 6.3 assists while playing 25.7 minutes per game.

"He's shown what some of his talents and abilities are," Skiles said of the 20-year-old Jennings. "He's still scratching the surface. We're asking him to think about a lot of things out there that ultimately will become second nature, and at the same time, be aggressive.

"We're asking a lot of him right now, but that's the nature of being a rookie point guard."

A worthy cause: The MACC (Midwest Athletes Against Childhood Cancer) Fund Game remains an annual event and has raised more than $1.2 million since the inaugural game took place on Dec. 10, 1976.

Current Bucks announcer Jon McGlocklin and former Bucks broadcaster Eddie Doucette founded the MACC Fund earlier that year.

The fund supports research into the effective treatment and cure of childhood cancer and related blood disorders. Much of this work is done at the MACC Fund Research Center at the Medical College of Wisconsin.

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