Kristian Campbell wasn’t in the starting lineup for the second straight game, but the Red Sox rookie still had plenty to do prior to Monday’s series opener against the New York Mets.

As has become routine over the past few days, Campbell ran through numerous drills at first base during pregame warmups. The Red Sox have acknowledged that they’ve begun the process of introducing Campbell to first in hopes he could become an option at the position, and bench coach Ramon Vazquez said that is the focus for him right now and that he isn’t dealing with any injury issues.

“He’s doing fine, another day for him to do a lot of work out there, working at first base, a lot of stretching, a lot of pretty much doing lunges, catching throws and he’s gotten better,” said Vazquez, who is serving as manager on Monday with Alex Cora away attending his daughter’s college graduation. “We’re giving him an extra day for him to reset and he’ll probably be ready to go in the next couple of days.”

Vazquez said Campbell has also been doing a lot of batting practice and other prep work, and that right now they just want him to clear his mind.

He added that Campbell has enthusiastically taken to his new assignment.

“He’s been great, since we introduced him to first base right away he was really into it, wanted to learn the new position, know everything,” Vazquez said. “He’s been the same old kid.”

Besides learning a brand new position on the fly, Campbell is also trying to work through the first real struggles he’s faced to this point in his professional career. Campbell rocked up through the minors with little resistance last season — his first full year as a pro — and he earned American League Rookie of the Month honors for April after a brilliant start to his big league career.

But since the start of May he’s fallen into a deep slump, going 4 for 47 (.085) over his last 11 games while watching his Wins Above Replacement mark fall from a high of 1.2 on April 30 to -0.1 entering Monday.

“It’s tough, at this level we all know how it is, how everyone prepares, once they get a little bit of information on you, they prepare for you, they prepare especially for you,” Vazquez said. “I think that’s something he’s finally dealing with and we saw the success at the beginning and slowly they’ve been getting to know him a little bit and it’s getting a little harder for him, but we know how good of an athlete he is, he has really good impressive skills putting the bat on the baseball.”

Vazquez suggested Campbell could return to the lineup soon, though with Cora away he hesitated to provide a specific plan.