SAN FRANCISCO — Jake Cronenworth woke up in his hotel room here Monday and knew it was time to figure out what was going on.

“I don’t drink much,” he said, “… and I woke up yesterday like I was hung over for like the fourth straight day.”

On Tuesday, Cronenworth was placed on the seven-day concussion injured list, 2½ weeks after he was hit in the head by a 97 mph fastball.

Sung-Mun Song was called up and started in Cronenworth’s place at second base.

Cronenworth will see a specialist when the team returns to San Diego after their series against the Giants.

“Since I’ve been hit, there have been good days, there have been bad days,” Cronenworth said. “Looking back at some of the days that I had, I probably should have said something a lot earlier. But I had never had a concussion, so I didn’t know what it felt like.”

Cronenworth said he was tested for a concussion after the pitch from the Angels’ Yusei Kuckichi grazed his shoulder and then hit him in the face on April 18.

“The only thing we’ve come to determine is I had so much adrenaline that it kind of just took over,” Cronenworth said.

He described being in a “hazy fogginess” many days since. He said he had difficulty focusing and trouble discerning the location of pitches and sometimes felt dizzy when making sudden movements.

The day after Cronenworth was hit, the Padres left Anaheim for Denver and then went to Mexico City. Being in the high-altitude cities for a week muddied the ability for Cronenworth to discern his symptoms.

“There are days that you have that you really don’t feel great when you’re (in elevation),” he said. “I couldn’t really tell. The first day we were in Colorado, looking back on it, was not a great day. But the next day was good, and then it kind of went back and forth. And since we’ve been since we got back from that trip from Mexico, it just hasn’t been good.”

Cronenworth was batting .144/.272/.196 in 114 plate appearances, not only his worst start to a season but his worst stretch of plate appearances in a career that began in 2020.

Song for real

Song joined the Padres for a couple days last month in Mexico City.

His MLB debut came April 26 as a pinch-runner, replacing Luis Campusano on second base. Song  scampered to third base on a wild pitch but never made it home, as Cronenworth grounded out to end the eighth inning.

In the short term, his joining the Padres is a simple swap. Song is, like Cronenworth, a left-handed batter who will play second base.

Whether Song faces just right-handed pitchers will be largely determined by how he does at the plate. Fernando Tatis Jr. has been moving in from right field to start in Cronenworth’s place occasionally.

Song will get a shot to establish himself as an option to play not only second base but be the Padres’ primary backup at shortstop and third.

“We’ll see how comfortable he is,” manager Craig Stammen said. “But now we have the opportunity a little bit to move him around the infield, get those guys days off.”

Song, who signed a four-year, $15 million contract in December,  never played shortstop in his nine seasons in the Korean Baseball Organization, but he got work there in spring training and while in the minors.

Song was sidelined much of spring by the recurrence of an oblique strain that first occurred in January. He began the season on the injured list, and the Padres kept him in Triple-A when his rehab assignment was finished to get experience.

Song spoke during the spring and again in Mexico City about getting used to the increased velocity he sees from major league pitchers, as well as the speed of the game overall being greater than in Korea.

“It was definitely time that I needed,” Song, who was batting .293/.364/.354 in 110 Triple-A plate appearances, said Tuesday through interpreter Juneseo Yi. “Coming back from injury, I had no feel for the game. Getting reps in Triple-A, playing multiple positions, helped me a lot.”

Tatis dropped

Tatis batted sixth in his 18th major league game, on April 13, 2019.

He led off for the Padres the next day and never batted lower than fourth in his next 677 starts.

Until Tuesday, when he was dropped to fifth in the midst of a start to the season that has seen him go a career-high 143 plate appearances without a home run.

“Just trying to switch it up a little bit, the whole entire lineup in general,” Stammen said. “And I think (for) ‘Tati’, just maybe taking a little bit of pressure off of him at the plate. Hopefully he can work on a few things and not feel like he has to get the job done in the five hole. Going two to five, does that really matter that much? I don’t know, but we’ll see. I think just shaking things up, putting people in different situations, different order, maybe it’ll turn their brains on a little bit, and we’ll ignite the offense.”

Jackson Merrill and Manny Machado moved up two spots from their customary spots to bat first and second. Miguel Andujar was third and Gavin Sheets fourth.

Tatis, who is batting .252 with four doubles and a triple, was intentionally muted about the move.

“I think nothing,” he said with a smile. “I’m here to play baseball, and that’s what I’m going to try to do.”

Left out

Left-hander Kyle Hart was not surprisingly the one caught in the necessary bullpen shuffle when lefty Yuki Matsui had to be activated off the IL.

Matsui, shut down in spring training due to an adductor strain, joined the Padres here Monday and was activated Tuesday. He had served the maximum allowable 30-day rehab assignment, and the five-year, $28 million contract he signed before the 2024 season stipulates he cannot be sent to the minor leagues without his permission.

Hart was the obvious arm to be optioned, given that the Padres also have left-handers Wandy Peralta and Adrian Morejón in their bullpen, and neither can be optioned.