With a solo homer in fourth inning against Houston on Sunday, Bay became the first Pirates player to homer in six straight games since Dale Long did it en route to a record eight in a row in 1956.
Bay already has set a Pirates record with 11 homers in May, breaking the record of 10 shared previously by five players. Coming off a breakout 2005 season in which he hit a career-high 32 homers.
To try and end Bay's streak, Milwaukee will send Doug Davis (3-3, 4.86 ERA) to the mound as he looks to win consecutive starts for the second time this season.
The left-hander held Cincinnati to two runs and five hits with four strikeouts and three walks over seven innings of a 6-2 victory on Wednesday.
Zach Duke (2-6, 4.36 ERA) will start a day earlier than planned when he takes the mound for Pittsburgh. Victor Santos was the scheduled starter in the opener, but Pittsburgh was forced to use him on Saturday in an 8-7 win in 18 innings.
"The program is set so that if there is a different day (to start) it's easy to recover," said Duke, a left-hander. "I'm going to be fully recovered."
Duke also is looking to avoid extending his career-high losing streak to five games. In his last four starts, Duke has a 5.76 ERA with 20 strikeouts and 10 walks in 25 innings.
The Brewers began the season with Brady Clark in the leadoff spot, but he couldn't get going in the opening month and manager Ned Yost switched to Rickie Weeks, who had been batting sixth. Weeks started a bit slowly in that new role but has taken off in the last week, batting .448 (13 for 29) with two homers. In 27 games batting first, Weeks is hitting .311 with five homers and nine RBI. "He's still just scratching the surface of what he can do offensively," said Yost.
BY THE NUMBERS: 16 -- Milwaukee has gotten 16 starts of seven innings or more.
QUOTE TO NOTE: "Brady looks like the Brady of last year now. If we get him going, we'll be in good shape." -- Manager Ned Yost, on his hope that CF Brady Clark has broken out of an early season slump.
RHP Rick Helling (sore right elbow) went on the 15-day disabled list retroactive to April 11. He could return in early June. RHP Tomo Ohka (partially torn rotator cuff) went on the disabled list retroactive to May 2. The Brewers hope Ohka can avoid surgery and return in the second half of the season.
RHP Ben Sheets went on the disabled list May 9 with shoulder tightness, and an MRI on May 22 showed no structural damage. He isn't expected to return until at least mid-June.
SS J.J. Hardy went on the disabled list May 17 with a severe sprain of his right ankle. He is expected to miss two to six weeks.
C Damian Miller left the game May 21 because of back spasms, and he didn't start May 22 or 23. He was back in the lineup May 24.