But the skipper dropped enough hints for a very educated guess: Corey Hart will stay in the leadoff hole, Weeks will bat eighth and either Gabe Gross or Tony Gwynn Jr. will be optioned to Triple-A Nashville.
Yost and general manager Doug Melvin planned to meet Monday morning to determine the roster move.
"It's going to be somebody who could get some at-bats," Yost said.
That applies to both outfielders. Gross was 1-for-14 (.073) in June entering play Sunday, and Gwynn 2-for-13 (.154). Gwynn has the edge defensively and is a better option to pinch-run, and Gross is more of a power threat. Both are left-handed hitters with Minor League options remaining, and Yost said both would benefit from regular playing time at Triple-A, in the same way Hart benefited when the Brewers sent him down midway through 2006.
The equally-compelling decision that faced Yost this week was who will hit leadoff when Weeks returns. Hart had hit safely in 16 of his last 18 games, batting .338 in that span and raising his average from .253 to .293. He was hitting .341 in 44 at-bats from the one-hole entering Sunday's start, and his overall on-base percentage was .374.
Weeks is batting .243 this season with a .345 on-base percentage and has scored 34 runs. He batted leadoff for all 53 of his starts this season.
"Rickie scores runs," Yost said earlier in the weekend. "Corey scores runs, plus, he drives in a bunch of runs."
By Sunday, the skipper seemed to have made his decision.
"There's going to be a lot of reasons Corey's staying in the leadoff spot," Yost said. "Of course, you want Rickie to go on a rehab so he can sharpen up, but we don't really want to do that. So he's going to have to sharpen up his offensive skills with us. I don't know if you can do that in the No. 1 hole or the eight-hole."
Weeks is on the DL because of soreness in his surgically-repaired right wrist. The Brewers expect Weeks to deal with soreness again later this season, so the decision was made to forego a Minor League rehabilitation assignment that would have "wasted" at-bats.
"When I put Corey in that role, I didn't put him there with a bunch of expectations," Yost said. "I just put him there. ... He's going to flourish no matter where you put him. Just because we put him in the one-spot didn't all of a sudden brighten his day and he started playing great. Corey's going to play great wherever you put him. He always has."
Line 'em up: In general, Yost believes too much has been made of his 43 different lineup permutations this season. He used eight different lineups on the road trip before Sunday, when the lineup was identical to Friday's series opener at the Metrodome.
"Everybody puts too much emphasis on guys hitting here, there, wherever," Yost said. "You're trying to put [together] guys who can get on base and guys who can create some type of sequence."
Speaking after the Brewers' series-opening win in Minnesota, outfielder Geoff Jenkins seemed to agree. He batted seventh on Sunday.
"Wherever you're at, you just have to go play and try to be your best," Jenkins said. "Obviously we've had a bunch of different lineups, and people said stuff about that. But regardless of where you hit in the lineup, how good the team is playing, lefty versus righty, whatever, you just have to go play. Don't worry about it."
Heady stuff: Brewers reliever Matt Wise wasn't injured after banging his forehead on the top of the visitor's dugout at the Metrodome on Saturday night. That was good news for the teammates who were anxious to wear him out about it.
Wise was upset after allowing a Joe Mauer triple in the seventh inning that scored a run charged to starter Dave Bush. He charged toward the dugout and smashed his head, an event caught on camera and replayed over and over throughout Saturday night and Sunday morning.
"I don't like giving up other guys' runs," Wise said. "That's something I pride myself on."
His train of thought was interrupted by closer Francisco Cordero, who walked by and slapped Wise on the forehead. Wise is no stranger to weird injuries, having cut the middle finger on his pitching hand when reaching for salad tongs last June 25 in Kansas City. He was well aware that the one-year anniversary of that unfortunate event is fast-approaching.
"I'm not going near a salad this week," Wise joked.
On deck: Assuming the Brewers could avoid using him in Sunday's series finale against the Twins, right-hander Yovani Gallardo was poised to make the most highly-anticipated debut by a Brewers pitching prospect since Ben Sheets' first start in 2001. Gallardo was scheduled to start Monday against the San Francisco Giants and left-hander Noah Lowry in the opener of a nine-game Brewers homestand.
Adam McCalvy is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.