Inside Tarik Skubal’s locker is a notebook he updates after every start to help him plan out his work before his next outing. He started doing it last year during his meteoric rise up the Tigers' farm system. He’ll check the notes as he watches video of his outing, and again before he throws his between-starts bullpen session. He notes the trends in starts and looks for points of emphasis.

His entry after Thursday’s 12-2 loss to the Cardinals in Game 1 of a seven-inning doubleheader will focus on one simple goal: Command.

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“I just didn’t command anything really well today, didn’t get into a good rhythm,” Skubal said. “And that’s something that I need to do a better job going forward; establishing that. New day tomorrow and get back to it.”

This is the process, and the Tigers fully committed to letting Skubal go through it when they called up Skubal and fellow top prospect Casey Mize to join their rotation last month. They’re not here to ride the I-75 shuttle between Detroit and Toledo, Ohio. They’re here to learn from their mistakes and to learn how Major Leaguers react to pitches compared to the hitters they faced on their way up here.

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Skubal’s fastball might have been good enough to get him through an outing with better results in Double-A or Triple-A. He’s learning how much smaller the margin for error is in the big leagues.

“I’ve got to have more than my fastball every time I go out there,” Skubal said. “I didn’t really even have command of my fastball today. I’ve gotta have more than one pitch every time I’m out there and work with it. That’s something I just need to do better.”

Skubal’s fastball drew seven swings and misses and nine called strikes. Harrison Bader and Lane Thomas both fanned on Skubal fastballs to strand a runner on second in the second inning, but Yadier Molina’s two-run homer off a high fastball earlier in the inning put St. Louis up to stay.

Skubal’s fastball comprised 49 of his 67 pitches, or nearly three-quarters of his outing. His 18 other pitches drew five swings, no misses, two called strikes and two balls in play, including Tommy Edman’s RBI double off a high changeup as part of four consecutive third-inning baserunners that chased Skubal from the game with nobody out.

It marked the second consecutive game the Tigers' bullpen had to cover innings instead of protecting a lead, following Matthew Boyd’s three-inning struggle Wednesday, and the game got out of hand. Joe Jiménez, who provided one of the few clean innings Wednesday against the Brewers, allowed home runs to Tyler O’Neill and Lane Thomas. Goldschmidt’s fourth-inning homer off Beau Burrows put St. Louis into double digits.

Add together the Cardinals’ early outburst, the Brewers’ 19-0 win Wednesday and Milwaukee’s attempted ninth-inning rally Tuesday, and the Tigers had sustained 31 unanswered runs between Jeimer Candelario’s two-run homer Tuesday night and his two-run homer Thursday off Cards ace Jack Flaherty.

Candelario’s sixth homer of the season marked the only runs allowed off Flaherty, who struck out six batters over five innings.

Skubal walked four of the 13 Cardinals he faced; three of those walks scored. He reached three-ball counts on three other hitters and threw first-pitch strikes to just six batters. His struggles came five days after he tossed six innings of two-hit, one-ball with six strikeouts against the Twins. It’s part of the up-and-down process a rookie endures, learns and in Skubal’s case, notes.

“I’m going to look at film and I’m going to look at where my pitches were and see if I can pick up anything and ... learn from it,” Skubal said. “But as far as lingering, it does no good. When I wake up tomorrow, it’s a new day. Get back to work, take care of the body, pick up a baseball and get to work preparing for the next one. ...

“It all starts with fastball command down and in. That’ll be the focus.”