DETROIT -- Justin Verlander returned to Comerica Park in Astros gear on Wednesday and handled the Tigers as expected, tossing seven strong innings with nine strikeouts in a 5-1 Detroit loss. Whether the Tigers can eventually claim victory in the deal that sent him to Houston is a long way off.

The final verdict on the trade completed 21 months ago won’t be known for another 21 months, maybe longer. The evidence wasn’t on the field at Comerica Park. It was spread out across the Tigers’ farm system, where the prospects Detroit acquired in the deal continue to develop.

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Hours before Verlander arrived at Comerica Park, Franklin Perez -- the prized prospect acquired in the trade with Houston -- took the mound in Clearwater, Fla., for Class A Advanced Lakeland in his first outing of the season. The big right-hander, baseball’s No. 71 prospect per MLB Pipeline, tossed four innings of one-run ball with three walks and three strikeouts after missing the first month-plus with a right shoulder sprain.

Around the same time Wednesday afternoon, top Tigers prospect Casey Mize -- selected last summer with the first overall pick in the Draft, which Detroit picked up with its September collapse following the Verlander trade -- took the mound for Double-A Erie and tossed five scoreless innings before giving up a pair of two-run homers in the sixth, his first home runs allowed this season. He struck out eight, giving him 48 over 50 2/3 innings this season to go with a 1.24 ERA.

Mize ranks sixth on MLB Pipeline’s Top 100 Prospects list. He’s the Tigers’ highest-regarded pitching prospect since Verlander climbed Detroit’s system 14 years ago.

A day earlier, catching prospect Jake Rogers -- also part of the Verlander trade -- made his Triple-A debut down the road in Toledo, having been promoted following a strong start at Double-A. He homered and doubled. Daz Cameron, also in the trade, had two hits Wednesday as the center-field prospect continues his slow climb out of a rough start.

Cameron could be the first to reach the Majors later this season, but Rogers’ promotion this week puts him in position to debut by season’s end. Even if they both end the year in Detroit, the final criteria for this deal will be how they fit into the big picture of the Tigers' rebuild, and whether they can eventually help Detroit return to the postseason.

On Wednesday, Verlander gave Tigers fans the kind of show he provided for the first 13 seasons of his Major League career. JaCoby Jones' third-inning home run was Detroit’s lone tally, not to mention the lone baserunner against Verlander through 15 batters.

“I knew he was going to throw me the slider down and away or try to come up again and make me chase. That’s what he does,” Jones said. “He elevates his fastball. I was just fortunate enough to get on top of it.”

Josh Harrison, who broke up a Verlander no-hit bid on this same field seven years ago, tripled in the fifth to begin a two-out rally that loaded the bases. Niko Goodrum, who homered off Verlander last July in Houston, hit a line drive with a 105.8 mph exit velocity and a 74-percent hit probability, according to Statcast, but second baseman Aledmys Diaz made a lunging catch to his left.

Verlander cruised from there, coming within a pitch of an immaculate inning in his seventh and final frame.

“He’s unbelievable,” Tigers manager Ron Gardenhire said. “He’s got great velo, has a great feel for what a hitter’s looking for. And he made it tough on us. We ended up with two hits -- a triple and a home run. That’s it for the night. That’s a very good pitching staff over there, and it was tough.”

The Tigers, using Gregory Soto as an opener with a depleted pitching staff, had no answer. If Mize and Perez develop as they hope, they could eventually have one.

The end goal, as Nicholas Castellanos pointed out a day earlier, is a team like the Astros. The three-game series sweep is a reminder of the gap.

“They’re very good,” Castellanos said. “We have to be like that, if that’s the goal. It just shows that we’ve got a long way to go.”