The unknown is out there, and Mark Teixeira is set to make the most of it.

That, in a way, always has been the secret to his success.

“This is a game you have to try to make fun,’’ Teixeira told The Post Thursday. “You can make it not fun and you can make it really difficult. Last year it was difficult, but because I missed the time, it’s a lot more exciting.’’

And how is it exciting, exactly, coming back from a wrist injury that essentially cost Teixeira the entire 2013 season?

“I kind of feel like a rookie this year because of the time off and the excitement of the little bit of the unknown,’’ Teixeira said. “How will I come back? Will I be the same player? Will I be better? There is some anxiety involved, but there’s also excitement.’’

Teixeira is out to show the world he can be the same player he was for the Yankees during the 2009-11 seasons — when he averaged 157 games, 37 home runs, 35 doubles, 114 RBIs, 102 runs, a .514 slugging percentage and an .877 OPS. Mix in some Gold Gloves, too.

The first baseman offered up his best swings of the spring Thursday in a split-squad 6-2 loss to the Phillies at Bright House Field, ripping a one-hopper off the chest of pitcher Roberto Hernandez then lining out to short right, where the third baseman was playing in the Phillies’ shift. In his final plate appearance, this time batting right-handed, Teixeira walked. He also had a couple of checked swings, reporting no wrist issues.

Teixeira, 34 next month, had surgery to repair the tendon sheath in his right wrist last season then spent six weeks in a cast. This has been a long road back.