One of the reasons the Yankees’ offense struggled a year ago was the inability of some key players to adjust to defensive shifts, especially Mark Teixeira and Brian McCann.

That’s one of the areas new hitting coach Jeff Pentland will focus on when the Yankees report to spring training in Tampa next month.

“We’ll talk about it,” Pentland said Thursday on a conference call. “The player has to buy in. The shift becomes almost a mental block sometimes. And it’s not only the Yankees. It’s a lot of teams that are going through the same situation.”

It will be up to Pentland and new assistant hitting coach Alan Cockrell to get the Yankees to adjust.

“You can’t completely change players, but we can certainly talk and work on making them understand that sometimes you’ve got to think more in the middle of the diamond than so much pull,” said Pentland, who acknowledged that it can sometimes be difficult for veteran hitters who have had success to make those alterations. “Do you change them or do you let them keep doing it?”

One young player the 68-year-old Pentland is looking forward to working with is Didi Gregorius, who is penciled in as Derek Jeter’s replacement at shortstop. Pentland watched Gregorius while he was with the Diamondbacks and liked what he saw.

“He started off very well, but just like most young hitters, they figure them out eventually,” Pentland said. “He’s an incredibly athletic player. He’s got a huge future. I’ve always thought there’s a lot in there. We’ve got to get it out.”

The left-handed Gregorius struggled last year against southpaws, finishing with a .424 OPS in limited opportunities, so Pentland knows he has his work cut out for him.

“The problem with younger players is you’ve got to be a little bit more patient,” Pentland said. “But I think this guy has a big upside.”

And he revealed another connection to the Yankees. It turns out he was roommates with Reggie Jackson at Arizona State, where Pentland was a lefty pitcher before switching sides and becoming a pitching coach.

“I was very good at pitching, I just hated it,” Pentland said. “I loved to hit. It was just that hitting was a little bit harder for me.”