SAN DIEGO — An MRI of Andrew McCutchen’s left knee Tuesday morning revealed the news the Phillies did not want to hear.

“My ACL is torn, so I’m out for the rest of the season,” the outfielder told reporters and Phillies broadcasters as manager Gabe Kapler sat behind a desk in the visiting clubhouse at Petco Park. “It’s a [lousy] dynamic.”

It was also a devastating blow for a team that has been in first place for 40 days, but was also in the midst of a five-game losing streak and a winless West Coast trip as it prepared to play the San Diego Padres on Tuesday night.

“Obviously everybody knows it [stinks],” first baseman Rhys Hoskins said. “This guy does more for this clubhouse than maybe he even knows. Yeah, it’s obviously a big blow. He’s a presence in this lineup, a presence on the team and the field. But I think we have to focus on the next-man up mentality on the field.”

The next man up in this case is Adam Haseley, who seven days after being promoted from double-A Reading to triple-A Lehigh Valley found himself making his major-league debut Tuesday night. He got the call from Lehigh Valley manager Gary Jones around midnight in his Pawtucket, R.I., hotel room.

“Probably just shock at first,” Haseley said when asked for his reaction. “I don’t really know what I said during the whole conversation, but I just kind of hung up the phone and sat there for a couple minutes and tried to take it all in.”

And then he started waking people up.

“I called everybody,” Haseley said. “I woke up my parents. My wife was still awake. She was trying to pack up the apartment [in Reading]. I called some of my friends and told them to get a plane ticket. I was calling everybody.”

Haseley, who went hitless in four at-bats in his big-league debut, said he expected about 10 people, including his mother, father and wife, at Tuesday night’s game at Petco Park. He batted eighth. His sense of excitement was understandable. The Phillies’ 2017 first-round pick became the second fastest position player from his draft class to reach the big leagues and all indications are he’ll have a chance to stick if he can play well.

“He is going to have a chance to play regularly,” Kapler said. “He has proven at the minor-league level that he is prepared for this. He has been on fastballs. He is improving defensively. He is not a finished product. There is still work to be done, but in order for him to really develop he’s going to need to play up here, play regularly and we’re going to find out how ready he is.”

Haseley, the eighth overall pick in the 2017 draft, is in just his second full season of professional baseball after being a two-way player (pitcher and outfielder) at the University of Virginia. Last season at high-A Clearwater and Reading, he batted a combined .305 with 17 doubles, five triples, 11 home runs and a .795 OPS.

This season at Reading and in six games with Lehigh Valley, he was hitting .275 with 11 doubles, one triple, seven home runs and an .824 OPS. He has played all three outfield positions during his three minor-league seasons, but the majority of his starts (110 of 207) have come in center field and that’s where the Phillies need him most right now.

“I’m confident that Adam will do a fine job in center field,” Kapler said.

As for McCutchen, he is headed to the injured list for just the second time in his career. Surgery will not be scheduled until the swelling in his left knee starts to subside and his range of motion increases.

“I can’t even straighten it out right now,” he said.

This is just the second time in McCutchen’s career that he has landed on the injured list, but his previous stay in 2014 with the Pittsburgh Pirates was a brief one. This is much different because now he will be a spectator for the remainder of the season. He said he will remain with the team whenever he can.

“Yeah, that’s the plan,” McCutchen said. “I want to stay around the team and be in the clubhouse. I can’t leave. I can’t be away from the guys. That wouldn’t feel right. I want to stay around the team as much as I can. Even though I won’t be out there physically, I’ll be in the clubhouse keeping these guys in the right state of mind and just rooting them on.”

That’s nice, but not nearly the same as being the guy at the top of the order who leads the National League in walks and ranks fifth in runs scored.