Alone atop the NL Central, the Pirates look to extend their longest winning streak in nine seasons to eight games while trying to hand the Brewers a fourth consecutive defeat Saturday night.
Pittsburgh (49-30) won six straight to conclude a 7-2 trip, then used a seven-run second inning to win 10-3 in Friday's opener to take a one-game division lead over St. Louis.
Owners of the best record in the majors, the Pirates have averaged 7.0 runs and clubbed 14 homers during the seven-game run - their longest since winning 10 straight from June 26-July 5, 2004.
"We're just playing really well," rookie pitcher Gerrit Cole told the Pirates' official website after he became the first Pittsburgh pitcher to win his first four career starts in more than a century Friday.
"Nothing crazy. When you play with that swagger, you put a lot of pressure on the other team."
McCutchen is 10 for 23 with two homers and five RBIs in his last five games versus Milwaukee (32-46) after going 6 for 25 (.240) in his first six this season.
Alvarez is batting .400 with 14 RBIs during his run to raise his average from .212 to .246. He went 2 for 22 in his first six against the Brewers in 2013, but is 5 for 11 with two homers and six RBIs in the last three.
Scheduled Pittsburgh starter Francisco Liriano (6-3, 2.30 ERA) allowed three runs and struck out 12 in 12 2-3 innings to split his last two starts. He gave up one of those runs in 6 2-3 frames of a 6-1 win over the Los Angeles Angels last Saturday.
The left-hander has allowed fewer than two runs six times in nine since he made his Pittsburgh debut May 11 after recovery from a broken forearm.
Liriano improved to 2-0 with a 2.89 ERA in his last three starts against the Brewers when he allowed a run and struck out seven in 5 2-3 innings of a 7-1 victory May 16.
Pittsburgh has won three straight and seven of nine versus Milwaukee following a nine-game skid in the series.
Outscored 22-9 during their-game skid, the Brewers' latest defeat came hours after they announced versatile star Corey Hart would need season-ending knee surgery. Rickie Weeks extended his hitting streak to 13 games and Carlos Gomez added two hits in his return from missing three games with a shoulder injury.
Despite his team's struggles, Weeks is batting .409 (18 for 44) during his run to raise his average from .195 to .236. However, he's 3 for 14 versus Liriano.
Rookie Donovan Hand (0-0, 2.37) makes his second career start for the Brewers on Saturday. The right-hander has made nine appearances out of the bullpen, including a scoreless inning Wednesday against the Chicago Cubs.
In his first start last Saturday versus Atlanta, Hand allowed two hits in 4 2-3 innings of a 2-0 victory.
"Donovan showed what you can do when you mix up pitches and you're throwing strikes, and how quickly you can get some outs," manager Ron Roenicke told the Brewers' official website.
Hand debuted May 26 when he allowed one run, three hits, a walk and struck out three in two innings of a 5-4 loss to the Pirates.
Milwaukee starters have an 8.57 ERA while losing four of the last five.