DETROIT -- Shohei Ohtani looked his manager in the eye and in just a few words, left no doubt of his intentions.

"I'll finish it," Los Angeles Angels manager Phil Nevin recalled Ohtani telling him after the eighth inning of what became his first complete game in Major League Baseball. "He wanted it. I could see it, too."

Ohtani polished off his one-hit shutout of the Detroit Tigers, then continued his extraordinary day in the second game of Thursday's doubleheader, hitting two homers to increase his major league-leading total to 38 before leaving the game with cramps.

The two-way superstar became the first player in major league history to throw a shutout in one half of a doubleheader and hit one homer -- much less two -- in the other.

Hours before Ohtani delivered the message to his manager, the Angels delivered one of their own.

The franchise, desperate to make the playoffs for the first time since 2014, made a win-now trade to bolster its pitching staff and confirmed that Ohtani will stay for the rest of the season before he becomes a free agent.

"We're going to roll the dice and see what happens," Angels general manager Perry Minasian told reporters before Ohtani led Los Angeles to a 6-0 win over the Tigers in Game 1 of the doubleheader, just days before MLB's trade deadline.

Ohtani's start was his best in the majors, a one-hitter with eight strikeouts on 111 pitches, including fastballs nearing 100 mph and wicked sliders and splitters that left the Tigers flailing.

In Game 2, Ohtani returned to the designated hitter role. The left-handed hitter hit a two-run homer to left in the second inning and a line drive to right-center in the fourth.

Ohtani became just the fifth player since 1900 to throw a shutout and hit two homers on the same day (single games and doubleheaders) and the first since Sonny Siebert in 1971, according to ESPN Stats and Information research.

It was just the latest display of why Ohtani could have landed a huge prospect haul in a trade, and why he's expected to cash in on perhaps the world's most lucrative contract in any sport this offseason.

Some speculate the 29-year-old might make $500-600 million on the open market , but the recent developments don't seem to affect his thinking.

"From the beginning, my plan was to finish strong this season with the Angels," Ohtani said through a translator after his gem on the mound. "I don't think things are really going to change mentally.

"But all the people talking about the trades, that's going to be all gone. So I feel like I'm just focused on taking this team to the playoffs."

The Angels are, too.

They're motivated to get rid of their reputation for wasting the talents of MVPs Mike Trout and Ohtani. The Arte Moreno-owned ballclub has the majors' longest streaks of consecutive losing seasons (seven) and consecutive non-playoff seasons (eight, tied with Detroit).

The Angels plan to hold onto Ohtani for as long as they can.

"I never went up to Shohei and said, 'Hey, we're not trading you,'" Minasian said. "Think I made it pretty clear the last time we talked, I think, that he wasn't going anywhere."

Another factor in the decision, a source told ESPN on Wednesday, was that the Angels have been underwhelmed by the players offered in return for Ohtani.

The 2021 AL MVP leads the majors in homers and OPS at the plate and is among the leaders in opponent batting average and strikeouts on the mound.

"He's doing the impossible," Tigers manager A.J. Hinch said. "We're playing against a generational talent."

When Chad Wallach tracked down a popup in foul territory for the final out of the fifth, Ohtani went out of his way to pick up the catcher's mask and hand it to him.

He really can do it all.

"I love Shohei Ohtani," Minasian said. "He comes in, prepares, works, goes out and performs on a nightly basis. Obviously, does both (hitting and pitching). He's a great teammate. He takes this really seriously. He eats it. He sleeps it.

"He's somebody that we would love to have going forward."

Aiming to bolster their chances of challenging for the AL West title or earning a wild card if they fall short in the division, the Angels acquired right-handers Lucas Giolito and Reynaldo López from the Chicago White Sox on Wednesday night. Giolito is expected to make his Angels debut Friday night against Toronto.

"I think this is the first time in my six years that we're buyers," Ohtani said.

The Angels also made another decision, designating 2021 All-Star slugger Jared Walsh for assignment. Walsh hit .119 with one homer and five RBI in 28 games this season, coming off an injury-stunted 2022. He's been struggling with headaches and insomnia this year.

"Gone through some hard times, and he's trying to find it back," manager Phil Nevin said. "I know he'll keep working. I hope he remains with us because I know when he gets on top of his game, we're a better team with him."

The Associated Press contributed to this report.