CHICAGO -- Tommy Pham passed a variety of tests on his tight right groin Wednesday at Wrigley Field after the finale of this series between the Cardinals and Cubs was pushed back a day. But he wasn't in the starting lineup for Thursday's makeup game after starting each of the Cards' first 17 contests.
Manager Mike Matheny characterized the decision to rest Pham as a way of being cautious with his starting center fielder, though Pham said he was physically fine to play.
"I thought it would be better if we gave him a day," Matheny said. "It's something he was feeling, so we'll try to avoid pushing it if we can. But the trainers feel very confident."
Matheny summoned Pham as a pinch-hitter in the seventh, and he flied out to end the inning in the Cardinals' 8-5 loss.
The Cardinals' most productive offensive player a year ago, Pham rebounded from a slow spring to hit .323/.440/.468 over the first 17 games of this season while playing above-average defense in center field as well. He originally felt his right groin tighten late in Tuesday's 5-3 win over the Cubs, after jogging to the outfield to begin the ninth inning.
Pham remained in the game, but only because the Cards had already used their fourth outfielder, Harrison Bader, as a pinch-hitter the inning before.
"He knew it wasn't something that had been pulled," Matheny said. "It was just a little something."
The injury did not require an MRI, but club officials briefly entertained the possibility of Pham having to miss time. They summoned outfield prospect Tyler O'Neill partly for this reason, and also in part to avoid similar depth-related issues going forward. O'Neill gives the Cardinals a five-man bench for the first time this season.

Wong waits for his chance
Kolten Wong wasn't in the lineup for the second straight game on Thursday, as Jedd Gyorko made his first start since returning from the disabled list. Gyorko started at third, pushing Matt Carpenter to second for the second straight game. The Cards' ostensible second baseman to begin the year, Wong expected to shuffle in and out of the lineup semi-regularly, as Matheny hoped to get him, Gyorko and Jose Martinez around five starts per week. But Martinez essentially won the first-base job outright with a torrid two weeks, narrowing the number of open positions to two.
That's consequently squeezing Wong, who began the season in a 6-for-40 funk without an extra-base hit.
"It's not tough for me, because I look at the big picture," Wong said. "We have so much talent on this team, we all knew coming out of Spring Training there would be guys who would be splitting time."
Wong said his offensive struggles stemmed from "not holding my back side," which messed with his timing and pitch recognition. By lunging forward too early, Wong's swing lacked balance. He believes his struggles were magnified given they came to begin the season.
"I know the player I am, I know what I can bring to this team," Wong said. "I'll have a good day and I'll get rolling, and I'll be back out there again. I'm a big believer in playing with rhythm."
Asked how he plans to find rhythm playing sporadically, Wong said: "That's the biggest question."
Martinez and Mikolas swapped
Inclement weather forced the Cardinals to switch their pitching plans for the second time this week. First they swapped Luke Weaver and Michael Wacha in the rotation so Weaver could start Thursday. Then they flipped Miles Mikolas and Carlos Martinez, opting for their ace to pitch Saturday against the Reds on just one extra day of rest.
Martinez was originally slated to start Sunday, which would've come on six days' rest.
"We don't want to give too many days to anybody, but when you have your No. 1 guy, you want to get him out there as often as possible," Matheny said. "Carlos is our guy. We made that statement Opening Day. So we try not to give him too many days of rest.
Martinez's career numbers improve considerably on an extra day of rest, then level out when given two extra days.
Four days' (normal) rest: 22-12, 3.56 ERA (50 starts)
Five days' rest: 21-11, 2.92 ERA (38 starts)
Six days' rest: 3-6, 3.40 ERA (16 starts)