Happ went 1-for-4 with a three-run home run in Tuesday's 5-4 loss to the Diamondbacks.
Webb (6-4) allowed two runs on one hit and one walk without recording a strikeout in one inning, taking the loss and a blown save in Tuesday's 5-4 loss to the Diamondbacks.
Holmes allowed two hits and two walks while striking out five over seven scoreless innings in a no-decision versus the Diamondbacks on Tuesday.
Harrison did not factor into the decision in Tuesday's game against the Mets, allowing one run on six hits and one walk while striking out five across five innings.
Kelly is absent from the lineup for Tuesday's game against the Diamondbacks.
Wynns and the Cubs agreed on a minor-league contract Tuesday.
Manager Pat Murphy said Tuesday that Gasser will be available out of the bullpen the next couple days versus the Mets, if needed, but remains lined up to start this weekend against the Rangers, Curt Hogg of the Milwaukee Journal Sentinel reports.
Mitchell (forearm) is starting in center field and batting seventh Tuesday against the Mets, Adam McCalvy of MLB.com reports.
Bauers is out of the lineup for Tuesday's game against the Mets due to some swelling in his foot, Adam McCalvy of MLB.com reports.
The Brewers reinstated Frelick (shoulder) from the 10-day injured list Tuesday, though he's not in the lineup against the Mets, Adam McCalvy of MLB.com reports.
