"There are guys in Nashville that I told to be ready, because you may be up and down two, three or four times," Melvin said. "It's a year where they just have to be ready."
The goal is to give the 23-26 Brewers a jolt, either offensively or on the mound, that will create success in the standings.
"We're hitting some bumps in the road, and we're not afraid to try some things," Melvin said.
Injuries also have played a role in the callups, especially in the bullpen. While Eric Gagne and David Riske are on the disabled list, it creates room for younger pitchers.
The three called up this week have been Mark DiFelice, Zach Jackson and Tim Dillard. Since they know they are filling in for pitchers who are injured, Melvin said he cautioned them not to read too much into any transactions.
"There are times when you're a player on the shuttle, and you might play well, but you get sent down anyway because we're looking for different roster needs at the time," Melvin said. "They've been around the game long enough to know the way the game is today."
Milwaukee manager Ned Yost said building reserves of players in Nashville who are available immediately is one of the team's goals each season.
"That's what we try to do at the beginning of every year, is get insurance down there, in case we need guys to step in up here," Yost said.
Russell Branyan was called up to give the team a left-handed bat, though it meant Tony Gwynn Jr. was sent back down to Nashville.
The team liked Gwynn's potential, but it was concerned about the effects of having a young player sit on the bench for long stretches.
Melvin said, relative to other teams, the Brewers tend to not make as many roster moves. But each one is geared towards finding a winning combination.
"As long as we perform and get on a hot streak, that's what we're looking for," the GM said. "We want to get the right mix."
Michael Phillips is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.