ST. LOUIS -- Shortly after feeling his mechanics click during a side session at Busch Stadium on Saturday afternoon, Luke Weaver learned that his next opportunity to take that adjustment into a game setting will come in a new role.
Interim manager Mike Shildt announced on Sunday that Daniel Poncedeleon will slide into the rotation and make the team's start in Los Angeles on Tuesday. That bumps Weaver to the bullpen, where Shildt said the right-hander will be deployed as a "shorter long man or a middle-innings guy" immediately.
With the swap, only one member of the Cardinals' Opening Day rotation (Miles Mikolas) has remained in that role uninterrupted.
"The results are the results," said Weaver, who entered Sunday's finale against the Brewers with a 4.67 ERA and 1.42 WHIP in 24 starts. "I need to be able to go out there and contribute. Things have been a little shaky, a little inconsistent. I understand that. I'm a good evaluator of myself, and I know some things need to be worked out.
"With this move, it's not a slap in the face. It's just about going out there and finding a way where I can help the team in a positive way."

Weaver believes he's already on that track. He identified a mechanical flaw on video after his 3 2/3-inning start last week and implemented the change during Saturday's bullpen session. Weaver threw exclusively fastballs and described the result as "amazing."
"There was a moment that I sat there and thought, 'Why did it take so long?'" he said. "It was a really good feeling to know what it felt like. The bullpen was maybe the best bullpen I had thrown all year."
Reclaiming fastball command will be key for Weaver, whose secondary pitches haven't been as effective without it. Extended counts and complicated innings have contributed to the inefficiency. Weaver, who is averaging 17.1 pitches per inning, has finished six innings in just one-third of his appearances this year.
"He's been dealing with getting a feel for his mechanics a little bit, getting the ball down a little bit more consistently," Shildt said. "We're really confident he's working toward that end with that session yesterday. This will give him a chance to work on a few things."
It will also give the Cardinals another chance to lean on Poncedeleon, who threw seven no-hit innings in his first and only Major League start. In the 'pen, Poncedeleon allowed four earned runs in 10 2/3 innings.

The Cardinals gave the nod to Poncedeleon over Tyson Ross, another former starter currently in the club's bullpen.
"It's about adjusting," said Weaver, who has made four career relief appearances with the Cardinals. "We have found ways to win with different puzzle pieces and moving people around. I want to be a big part of the stretch down the road, and I feel like I definitely will be. At the moment, they think this is the best move. I'm just going to do what I can."
Medical report
Kolten Wong (right elbow contusion) and Jose Martinez (right hip soreness) are expected back in the lineup for Monday's series opener in Los Angeles, Shildt confirmed after the Cardinals' 2-1 loss on Sunday.
Wong, who was struck in the elbow by an errant pickoff throw on Saturday, made a pinch-hit appearance on Sunday. Martinez did not start either weekend game, but he also came off the bench for one plate appearance.

Reinforcements coming
Yairo Munoz (right wrist sprain) and Carlos Martinez (right shoulder strain) are headed back to St. Louis for evaluation after making rehab appearances with Double-A Springfield on Sunday.
Martinez threw 15 pitches (12 strikes) in the rain-shortened game. He struck out one while facing the minimum in an inning of relief. Weather precluded Munoz from playing nine innings, as planned. He went 1-for-2 with a double while playing center field.
Assuming both players pass all necessary medical tests, they will fly to Los Angeles to join the big league club. Both could be activated from the disabled list as soon as Tuesday.
Rehab roundup
• Adam Wainwright (right elbow strain) threw two scoreless innings in his first rehab appearance for Springfield. Wainwright allowed one hit and struck out four while throwing 18 of his 27 pitches for strikes.
• Michael Wacha (left oblique strain) will make another start for Springfield on Thursday, Shildt confirmed. Wacha threw 27 pitches over two-thirds of an inning to open his rehab assignment on Saturday.
• John Brebbia (right forearm strain) began his rehab stint for Triple-A Memphis with a one-inning appearance on Saturday. He allowed one run on one hit and struck out two.
• Dominic Leone (nerve irritation) scattered two hits over a scoreless inning in his eighth rehab appearance with Memphis. Thus far, Leone has had each of his outings scripted ahead of time. Moving forward, Shildt said, Leone's work will be less predictable. That will help him get used to coming out of the bullpen in varying situations.