Carlos Carrasco’s torn right hamstring, which the Mets initially hoped would cost him six to eight weeks, is now guaranteed to keep him sidelined for significantly longer than that. The team on Thursday transferred Carrasco to the 60-day injured list, which will prevent him from returning before May 31.

Mets officials said that while Carrasco did not suffer a setback such as a re-tear of the hamstring, he also hasn’t been able to push the muscle as much as he would like. Carrasco has been pitching in simulated games at the Mets’ Spring Training complex, but he also must prove that he can field his position at game speed before the team will consider activating him. When the Mets pushed Carrasco in workouts this month, his hamstring did not respond as they had hoped.

“He has done everything … it’s just right now, he hasn’t done it at game speed,” manager Luis Rojas said. “We still want to do that a little more before he joins us, and still take it with care.”

Now on the 60-day IL, Carrasco will have additional opportunities to prove his health in Minor League games. The Mets scratched him from a potential start this weekend at Triple-A Syracuse but hope to have him begin a Minor League rehab assignment by the later part of May. Rojas indicated Carrasco will need “one or two” rehab starts before joining the Mets.

“We reassessed the timeline,” Rojas said. “There are some things we still want to test on the field.”

Transferring Carrasco cleared 40-man roster space for the Mets to activate reliever Tommy Hunter, who had the right to opt out of his Minor League deal if the Mets did not add him to the roster. To make room for Hunter on the active roster, the Mets optioned right-hander Jordan Yamamoto to Triple-A.

Carrasco, 34, was the second piece the Mets received from Cleveland in their Francisco Lindor trade this winter. He went 88-73 with a 3.77 ERA over 11 years with Cleveland, but health problems and the pandemic have limited him to 24 starts over the past four seasons. In his absence, the Mets have relied mostly on Joey Lucchesi to fill their rotation hole; Lucchesi is due to pitch bulk innings on Saturday.

Mets considering prospect callup
With Brandon Nimmo on the injured list, the Mets have instructed seventh-ranked prospect Khalil Lee to be ready for potential activation this weekend, according to multiple sources. Lee played in each of Triple-A Syracuse’s first two games on Tuesday and Wednesday, after which he was told he could receive a callup.

The Mets did not send Lee to join the team in St. Louis. Instead, team officials told him to be prepared to come to New York for the start of the team’s three-game series against the D-backs this weekend.

The Mets acquired Lee from the Royals this offseason as part of the three-team trade that sent Andrew Benintendi from Boston to Kansas City. A 22-year-old with speed and power, Lee hit .264 with eight home runs and 53 stolen bases in 129 games at Double-A in 2019. But he also struck out 154 times and looked overmatched at times in big league camp this spring, going 0-for-16 with nine strikeouts and making several defensive misplays.

If the Mets do activate Lee, it would not be for a starting role. Instead, they would expect him to provide speed and defense off the bench, with Kevin Pillar and Albert Almora Jr. starting most games in center. The Mets hope that Nimmo, who is nursing a bone bruise in his left hand, can return as soon as he’s eligible next weekend against the Rays.

“It really just came down to our team needed someone who’s available right now, and that wasn’t me,” Nimmo said. “The hand is trending up, it’s coming along, just not quick enough for what we need right now.”

Mets officials have also discussed activating outfielder Johneshwy Fargas, who traveled with the club to St. Louis on its taxi squad. But unlike Lee, Fargas is not on the 40-man roster, so activating him would require clearing a roster space. To that end, the Mets could consider shifting reliever Seth Lugo to the 60-day injured list to clear a spot, since he is not due back from right elbow surgery until late May, but doing so would ensure Lugo’s absence until at least May 31. They could also designate a player for assignment.

Or they could activate Lee, despite questions about his readiness.

“We’re talking about it,” Rojas said, “in case we need it for the weekend.”

Still on track
Jacob deGrom played catch up to 90 feet on Thursday after refraining from throwing for two days. Assuming he recovers well, deGrom (right lat soreness) will attempt to throw a bullpen session Friday at Citi Field. He remains lined up to return to the rotation this Sunday against the D-backs, having missed just one start.

David Peterson will start the three-game series opener at Citi Field. The Mets remain undecided on their Saturday starter, though Lucchesi is likely to pitch bulk innings in that game. If he does not start, he will come in behind an opener.

Friendly face
As Lindor sat out Game 2 of Wednesday’s doubleheader in St. Louis, he spent time chatting on the bench with a friend: Kevin Howard, the Mets’ new assistant hitting coach. Howard overlapped with Lindor for six seasons in Cleveland’s organization. Even though his work was mostly on the Minor League side, he came to know Lindor from their shared experiences, particularly during Spring Training.

“Personality-wise, he’s a player that wants to be the best at all times every single day, and I think that can get in the way of development sometimes,” Howard said of Lindor, who snapped his 0-for-26 slump with a ninth-inning single on Thursday. “You can’t always ‘try’ your way out of being the best player. When things aren’t going well, it’s not an effort thing sometimes. Francisco’s a player that gives 100 percent effort 100 percent of the time. And that’s the tough thing about hitting -- sometimes it’s not how hard you’re trying, it’s specifically what you’re working at.”

From the trainer’s room
• Luis Guillorme (right oblique strain) expects to return from the injured list as soon as he is eligible on Sunday. His return would likely push infielder José Peraza back to Triple-A.

• Edwin Díaz (back soreness) has been available out of the bullpen since Wednesday. He entered with a three-run lead in the ninth on Thursday. Díaz allowed two singles but buckled down to notch his fourth save of the season.