Former Mets ace Matt Harvey will look to regroup as a reliever, as he will be available out of the bullpen beginning Tuesday night in St. Louis.

Harvey, 29, went 0-2 with a 6.00 ERA over four starts for New York this season before he was bounced from the rotation.

It’s been a rapid decline for the artist formerly known as The Dark Knight, who has endured Tommy John surgery and a procedure to relieve Thoracic Outlet Sydrome. This has subsequently led to a decline in velocity, movement and predictable pitches.

Former Met Bob Ojeda weighed in on Harvey, and said the move to the bullpen will be an effective one for the right-hander

“His stuff has changed, it’s not what it was and I still 100 percent believe he doesn’t know how to pitch,” Ojeda told The New York Post on Monday.

“It’s not, ‘I throw 30 percent changeups, I throw 85 percent fastballs, I throw 12 ¹/₂ percent knuckleballs.’ No. Pitching is feel,” he continued. “Now he’s going to go out there presumably twice a week, maybe more, and going to have to learn on the fly how to get people out. He’s getting thrown in deep, I love it.”

Mets manager Mickey Callaway has had great success with pitchers who were moved to the bullpen out of the starting rotation. During his time in Cleveland, he helped get pitchers Danny Salazar, Carlos Carrasco and Trevor Bauer back on the right track.

“This is the right move and it was worded the right way,” Ojeda said. “It didn’t become, ‘Let’s banish him, let’s punish him.’ It was, ‘Look, you have some stuff to work on and we are going to throw you in the pen.’ They have a rotation that is volatile, like a lot of rotations, so he can spend some time in the pen and he may pitch himself back into the rotation, if the door opens, but if not he stays in the pen.”

Ojeda added that moving Harvey to the bullpen also sends a message to other guys on the team that if they aren’t performing, there will be consequences.

“What I like is it becomes what’s good for the New York Mets,” Ojeda said. “That is a message that the other men in the locker room see. It’s like, ‘OK, it’s what is good for the team,’ and Matt understandably was upset because all of a sudden you get fired from your job that you have basically had forever. And then you have got a new job.”

Hall-of-Famer John Smoltz knows exactly what Harvey is going through.

In 2001, Smoltz was moved to the bullpen by the Atlanta Braves after missing the previous season with Tommy John surgery.

Smoltz went on to become a dominant closer for several seasons before re-entering Atlanta’s rotation in 2005 — a year he made it to the All-Star game and finished 14-7 with a 3.06 ERA.

The 21-year veteran said it’s important to be patient with Harvey and give him a break, because he’s trying to adapt to a new role.

“I don’t think it’s fair to write off a Matt Harvey if not given the opportunity to have enough time to go through this,” Smoltz told the New York Daily News. “That’s the dilemma. What is that time frame you are willing to deal with in that organization? A new manager who has seen in Cleveland this work for an array of guys. He believes this will work for Matt. Now, it’s up to Matt to believe it.

“It won’t be right away, but long-term, if the Mets are going to be in the playoffs and they need the depth that this rotation and this bullpen could use, then he could be a vital, vital part,” Smoltz continued. “But it is going to be a process.”

At the end of the day, Smoltz says that Harvey is going to have to get through the emotional side of things and adapt to his new role as a reliever.

“You really got to be mentally open to unknown scenarios, opposed to the structure you loved as a starter,” Smoltz said.

“I had to let go of everything I couldn’t control and let happen whatever would happen.”

For Harvey, it will be a transition, but for now he needs to focus on succeeding in the bullpen and work towards getting back into the rotation.