Yost gave no indication that he planned to begin splitting time between Durham and Weeks at second base, and that question may have been rendered moot when Durham fouled a ball off his right shin in the third and left the game in the seventh.
On Monday, Weeks committed a key seventh-inning error that contributed to two Cubs runs in an eventual 6-4 Brewers loss. He also went 0-for-4 at the plate.
"Generally, I don't change the lineup because a guy missed a play or made a mistake in the field," Yost said. "That had zero to do with it."
Still, the switch was also notable because it was not clearly driven by the numbers. Weeks, a right-handed hitter, entered the night with a career .250 average (7-for-28) against Zambrano while Durham, a switch-hitter, was hitting .267 (5-for-15). This season, left-handed hitters were batting only three points higher against Zambrano than right-handers (.244 to .241).
Yost has been a strong supporter of Weeks, who is hitting .224 with a .330 on-base percentage this season and leads the team with 66 runs scored. When the team traded two prospects to the Giants for Durham, Yost was clear that Weeks would remain the regular second baseman.
So far that plan has held. Durham has started three of Milwaukee's nine games since the trade, including Tuesday's matchup against Zambrano and the Cubs.
"When I talked to [Giants manager] Bruce Bochy about him when we made the deal, he said that Ray has gotten to the point that when he's rested enough, his game will really elevate," Yost said. "When he gets in trouble is his legs get beat down and he has trouble with his hamstrings. If he's playing three, four days a week, he'll be able to steal bases, he can hit for power and he hits very good pitching."
Defensively, Durham is average to a tick below average, according to Yost. Weeks, the skipper acknowledged, remains below average.
"But he has gotten so much better," Yost said. "He is stiff at times and he speeds up at times. ... He will get to 'average,' because he has the work ethic to do it. Rickie's a kid that works as hard as anybody I've ever seen and has the mental makeup and strength to work through it.
"When you struggle like he's struggled the last couple of years, a lot of people don't have the mental makeup to survive that. They fold. Rick doesn't let that affect him. He's very, very strong mentally. If he makes a mistake it hurts him, he doesn't like it, but he continues to work hard to overcome that."
Weeks' bat has come around. Even including Monday's 0-for-4, Weeks was hitting .320 with a .379 on-base percentage, five runs scored and five RBIs since the team acquired Durham. In 16 games since July 6, Weeks was hitting .300 with a .394 on-base percentage, 16 runs scored and nine RBIs.
"Rickie's ceiling ... is maybe not higher than Braunie's [Ryan Braun], but he has the talent and ability to be a spectacular player, offensively," Yost said. "He's got a bat as quick as anybody in the game -- the strength to be a big-time power hitter."
Some have questioned whether the Brewers, who have indicated clearly by the acquisition of players like CC Sabathia and, to a lesser extent, Durham, that they are in "win now" mode, can continue to wait for Weeks to reach his potential.
Yost and general manager Doug Melvin apparently are not in that camp. Yost said that in the days before the Durham trade was made official, there was never any discussion of platooning Durham and Weeks at second base in the same way Hall and Russell Branyan have split time at third.
"We were looking for another bat, a left-handed bat, and [Durham] was the best one we could find that was available and would fit as an extra infielder," Yost said. "There was no, 'Boy, we have to find a second baseman.' You're leading into something that's not there."