PHOENIX -- Though neither the Arizona Fall League, nor the Pirates, have made it official, Gerrit Cole, the No. 1 overall pick in the 2011 First-Year Player Draft, is expected to soon be named to the AFL's Mesa Solar Sox roster.

The Pirates have always left the door open to Cole's participation in the AFL, though a decision was going to come after the right-hander worked out and engaged in a throwing program in front of organization eyes in Bradenton, Fla. Cole is still in Bradenton for instructional league workouts, but he will leave early to head to Arizona.

Cole will be joined by six other Pirates prospects -- lefty Nathan Baker, right-handers Phil Irwin and Mike Colla, infielders Jarek Cunningham and Brock Holt and outfielder Robbie Grossman. All six have already been officially announced.

The AFL season will begin on Oct. 4. Triple-A Indianapolis hitting coach Jeff Branson will serve as the hitting coach for the Mesa club.

General manger Neal Huntington said all of the pitchers will have varying workload limitations. Because he hasn't pitched in a competitive environment since the end of his collegiate season, Cole will likely be less limited in his innings count this fall.

Pirates leave winter-ball decision up to Alvarez

PHOENIX -- Often undeservedly, Pirates third baseman Pedro Alvarez has been a lightning rod for criticism from fans who have been displeased with his development and results since being taken with the second pick of the 2008 First-Year Player Draft. Lately, the murmurs have centered around his perceived desire -- or lack thereof -- to play winter ball.

While Alvarez has not yet made a decision about whether he will participate in winter ball, general manager Neal Huntington made it clear on Monday that the organization is not adamant that Alvarez plays this winter. There are, Huntington explained, pros and cons to either route Alvarez can take.

"We see both perspectives," Huntington said. "One perspective, which is a genuine and legitimate one, is that it might be better for him to just take a deep breath and come into Spring Training ready to go. There is [also] the perspective that it would be good for him to go down and get at-bats and try to salvage what has been a very difficult year for him."

Winter-ball assignments are not always so clear-cut, either. While it would be a natural fit for Alvarez to play on the Dominican Winter League club managed by Pirates Triple-A skipper Dean Treanor, Alvarez is automatically assigned to the DWL club that drafts him. Alvarez would only be able to join another club if a trade can be worked out.

Discussions about Alvarez's offseason plans are ongoing, and a decision about winter ball may not come before the end of the regular season.

"[It] ... shouldn't be portrayed as anything negative on Pedro should he choose not to go," Huntington said. "There are other times where we have wanted guys to go and they haven't. This isn't one of those times. This is one of those where we have to do the right thing for the player and he has to do what he believes to be the right thing. There are valid arguments on both sides."

Rotation for final week won't include Karstens

PHOENIX -- In addition to announcing that Jeff Karstens would not make another start after Monday's outing against the D-backs, manager Clint Hurdle laid out rotation plans through the end of the season. Karstens is the only member of the current rotation set to be unplugged.

That means that after Charlie Morton and Ross Ohlendorf start games in Arizona, Jeff Locke, Brad Lincoln and James McDonald will pitch in the upcoming three-game series against the Reds at PNC Park. Morton and Ohlendorf will return for their final outings of the year in Milwaukee.

The only unknown, at this point, is who will pitch the Pirates' final game of the season. That Sept. 28 start against Milwaukee could go to Locke, Brian Burres or Aaron Thompson. Hurdle also didn't rule out a bullpen-by-committee approach to get through that game.

The decision to shut Karstens down is due entirely to his innings count. He has already thrown 156 1/3 innings, which is 33 2/3 more than he tossed in the Majors last year. Monday's outing was Karstens' fifth shot to notch win No. 10 this season. He has just one victory in his last nine starts.

Bucs Bits

• The Pirates plan on having their traditional mini-camp next January in Bradenton, Fla. The club is still working through the structure of the program. In addition, general manager Neal Huntington said on Monday that the organization will hold a separate winter mini-camp in Bradenton for a select group of prospects.

• Pittsburgh has not won a series at Chase Field since 2005, when it took three games in a four-game set. The Pirates are 4-12 in Arizona since the start of the '06 season.

• Monday marked Jeff Karstens' first start at Chase Field since Aug. 8, 2008, when Karstens came four outs away from throwing the first perfect game in franchise history. He faced only two batters over the minimum in that two-hit shutout.