A seven-game losing streak contributed to that deficit currently standing at six, but Pittsburgh has a prime chance to make up some ground as it visits Miller Park for a three-game series beginning Friday night.
The Pirates' push for a second straight playoff appearance took a hit with their extended skid, though they snapped it with their 32nd comeback win of the season in Wednesday's 3-2 victory over Atlanta on Gaby Sanchez's walkoff sac fly.
Pittsburgh (65-62), which is fourth in a tight wild-card race, plays nine of its next 12 against the Brewers and second-place St. Louis.
''We don't ever feel like we're down,'' Sanchez said. ''It doesn't matter if we're down by four or five. We can still come back and win a ballgame.''
The Pirates have lost seven of 10 meetings with Milwaukee this season - including five of six at Miller Park - but the Brewers know they're about to face a club desperate to get back into the Central race.
"The Pirates are looking to rebound right now, so we need to come out and still do our thing and make sure we stay on top," said Brewers reliever and former Pirate Zach Duke. "This is where everybody wants to be. You want to be in contention when this time of year comes around. That's what makes it fun."
Milwaukee (71-56), which has been in first place since April 5, had won five straight before Wednesday's 9-5 loss to Toronto. The Brewers look to bounce back with help from Yovani Gallardo, who has been hot lately and has had plenty of success against Pittsburgh lately.
Gallardo (8-6, 3.32 ERA) has won his last two starts on the road, giving up one run in seven innings of a 3-1 win over the Chicago Cubs on Aug. 11 and one in eight innings of Saturday's 3-2 victory over the Los Angeles Dodgers.
The right-hander is 3-1 with a 1.60 ERA over his last four outings, pitching at least seven innings four times.
''Yo was just outstanding,'' manager Ron Roenicke said after Gallardo beat the Dodgers. ''He had great command and an outstanding fastball. He really dominated."
Gallardo is 2-0 with a 2.06 ERA in his last six starts against the Pirates, including four this season. Most recently he allowed four hits and struck out eight in seven innings of a 1-0 victory June 8.
He opposed Jeff Locke in that contest, and they'll face each other again Friday. Locke (4-3, 3.73) gave up one run and three hits in seven innings to suffer the tough-luck loss in that matchup.
The left-hander allowed four hits in 5 2-3 scoreless innings of Pittsburgh's 4-3 loss to Washington on Saturday, a vast improvement after going 2-2 with a 6.38 ERA over his previous four outings.
It also marked the 10th time this season Locke left with a lead, but he's only earned four wins in those outings.
"(Blown leads are) a collective effect, because we're all trying to get to the same place," Locke said. "It'll get scary when we get rolling."
Locke hasn't had much success against Jonathan Lucroy, who is 4 for 8 with a homer, a double and three walks in their matchups. Lucroy is in the midst of a stellar season, with his 42 doubles leading the majors.
No catcher in modern baseball history has ever led baseball in two-base hits, but Lucroy isn't focused on individual accolades.
"Honestly, I want that ring, man," Lucroy told MLB's official website. "That's what I want. Period."