ST. LOUIS -- It’s easy for the Cardinals to dream about what Alex Reyes could one day become. His repertoire screams of a potential ace.

Right now, however, the longtime top prospect remains a work in progress, evidenced by another erratic performance that soured a celebratory home opener at Busch Stadium on Friday. Making his first appearance at Busch Stadium since 2016, Reyes saw his command once again abandon him in a key seventh-inning spot.

With Fernando Tatis Jr. delivering the dagger in a city where his father was once so beloved, the Padres scored three times off Reyes to tip a tie game their way. San Diego then held on for a 5-3 victory in front of the sellout crowd.

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“It comes down to executing the pitch, and I haven’t been able to do it,” Reyes said afterward. “My arm feels fine. My body feels healthy. It’s more of just going out there and me handling my job."

Friday was to mark another milestone for Reyes, whose last appearance at Busch Stadium had come before two surgeries wiped out nearly two full seasons. It marked his first time as a participant in the home-opener festivities.

But since making his season debut with a clean inning at Miller Park on Monday, Reyes has been searching for consistency and command. His last three appearances have all been complicated by walks, and in each one, he’s been unable to escape unscathed.

“Clearly, you’d like to see more consistent strikes,” manager Mike Shildt said. “Obviously, the stuff is there. The weapons are there. You like weapons when guys are on base. You just don’t like to put them there."

The seventh went off script quickly as Manny Machado worked out of an 0-2 count to draw an eight-pitch leadoff walk. Franmil Reyes followed with another free pass. A wild pitch moved the two runners into scoring position and left Shildt with a decision to make after Wil Myers grounded out for the inning’s first out.

He had groundball specialist Dakota Hudson ready in the bullpen, but Shildt opted to have Reyes face Franchy Cordero, who entered the game with a 43-percent strikeout rate. Reyes fell behind and couldn’t get the punchout. Instead, Cordero lofted a sacrifice fly to center to plate the go-ahead run.

“That was probably the call of the game,” Shildt said. “Give Cordero credit. He put together a patient at-bat and got a sac fly.

Tatis followed with a first-pitch home run to tack on two insurance runs.

“I got goosebumps and everything,” said Tatis, who had earlier received a warm ovation from the St. Louis crowd. “It was a very special moment."

Reyes issued one more walk before finally closing the inning on his 26th pitch. He’s now walked six in three innings out of the bullpen, where the Cardinals have used him in a variety of high-leverage spots.

When and how he’s deployed may change, however, while the club gives Reyes time to sort out his mechanics.

Much of his trouble seems to stem from his delivery, which he hasn’t been able to repeat with much consistency. Reyes is also searching for command, in particular, of his offspeed pitches. Of the nine changeups Reyes has thrown this season, one has finished in the strike zone. It’s the same ratio with his slider, according to Statcast data.

“I feel good. My stuff is coming out with life,” Reyes said. “It’s about getting the ball down and being able to consistently execute quality strikes. I’ve just got to be able to do it. I’ve got to go out there and be able to execute.