Andrew McCutchen is shaving his beard for a possible World Series run. Ryan Madson is switching bullpens, trying to help another team win a title.And Gio Gonzalez? He might be moving across the diamond at Nationals Park.A bunch of contenders got busy Friday, making trades to bolster potential playoff rosters. A player must be on a club by Aug. 31 to be eligible for the postseason.Relievers are always in demand, and the Milwaukee Brewers fortified themselves by acquiring veteran left-hander Xavier Cedeno from the Chicago White Sox for two minor leaguers.The Brewers also seemed to be close to getting Gonzalez from Washington to boost their rotation. Milwaukee was playing at Washington, so a trade would mean simply swapping dugouts."I think what happens in September is that the whole calculus of this thing changes," Milwaukee manager Craig Counsell said.Clubs can start calling up reinforcements from the minors on Saturday. But it's who they added before September that could really count in October.McCutchen, one of several players to pass through waivers after the July 31 trade deadline, was sent from San Francisco to the New York Yankees for a pair of minor leaguers.The 2013 NL MVP was hitting .255 with 15 home runs, 55 RBIs and 13 stolen bases for the Giants. McCutchen will take over in right field — that was slugger Aaron Judge's spot in the Bronx, but he hasn't swung a bat since a fastball broke his wrist five weeks ago.The 31-year-old McCutchen was expected to be in the lineup Saturday at Yankee Stadium to face Detroit. Before he plays, though, he must adhere to the Yankees' strict rule on facial hair, and that meant shaving the beard he's sported for almost his whole career."Just gonna take me a sec to get used to my freshly shaved face," he posted on Twitter.The Los Angeles Dodgers, having seen closer Kenley Jansen wobble since coming off the disabled list, got Madson from the Nationals for a minor league pitcher.Madson was 5-5 with five saves and a 4.08 ERA in 69 games for Washington. The 38-year-old recently came off the disabled list after being sidelined by nerve irritation that caused pain in his neck and back."Feels like a fresh start, especially to a year I've struggled a little bit," Madson said as he was leaving Nationals Park. "Now none of that matters. All that matters is from this point forward and helping that team win games. That's it."Madson helped Philadelphia win the World Series in 2008 and Kansas City do the same in 2015.The Oakland Athletics, who finished last in the AL West the past three years, tried to improve their playoff chances by getting right-handed reliever Cory Gearrin from Texas Rangers for a pair of minor league pitchers.Gearrin was a combined 2-1 with a 3.51 ERA and one save in 56 appearances for the Rangers and San Francisco."I know he's excited about being here. I talked to him for a while today, he said, "I'll do whatever you ask me to do,'" A's manager Bob Melvin said.In another deal, the Colorado Rockies got backup catcher Drew Butera from Kansas City for a minor league lefty.