David Robertson, who has not discussed a contract extension, said he is content to finish the season before talking to the Yankees about his future and said the team might have saved itself money had it attempted to sign the closer last winter.

“I thought the calls would come but at this point right now I am going to wait and see how the season plays out,’’ Robertson said before the Yankees’ 5-1 win over the Tigers Wednesday at the Stadium.

Asked if he would ignore an offer and wait to become a free agent following the season, Robertson didn’t shut the door completely but explained the offer would have to be significant to discuss it.

“It would have to be a legit offer at this point of the year,’’ said Robertson, who has converted 30 of 32 saves and has proved to everybody that replacing Mariano Rivera wasn’t too tall of a task.

With Rivera gone after the 2013 season and Robertson the apparent replacement, he would have considered staying for less.

“This offseason I probably would have gone for a discount, although I wasn’t a closer,’’ said the 29-year-old right-hander, who is making $5.215 million in a walk year.

The Yankees aren’t known for locking up players before they hit free agency, but they have done it. This past spring training they signed Brett Gardner to a four-year deal worth $52 million that starts in 2015 to keep him off the free-agent market. Gardner said he didn’t want the hassle of being a free agent.

General manager Brian Cashman gave a “No comment’’ when asked if the club would make an offer to Robertson before the end of the season.

Asked if he was puzzled by the lack of an offer, Robertson said he wasn’t.

“Not at all, it seems the way they do business around here,’’ he said. “I have been to arbitration three times. It’s not like I don’t like playing here, but I have to do what’s best for me.’’

The Yankees, who will have Dellin Betances waiting to close if Robertson splits, likely will drop the one-year qualifying offer on Robertson. This past offseason it was $14.1 million and not once in the two-year history of the qualifying offer has a player accepted it. That may change this winter after what happened to Stephen Drew and Kendry Morales, who had to wait until late May and early June, respectively, to sign free-agent deals with the Red Sox and Twins.

The only closer ever offered the qualifying offer was Rafael Soriano by the Yankees following the 2012 season. He rejected it and signed a two-year, $28 million deal with the Nationals.

Masahiro Tanaka resumes playing catch Thursday after taking Wednesday off. Tanaka tested his right elbow with light catches Monday and Tuesday.

Manager Joe Girardi doesn’t have a starter for Friday night’s game against the Indians at Yankee Stadium. The need for a starter was created when David Phelps went on the DL this week.

“I won’t know until maybe Thursday night, because of the guys I might use the next two games,’’ Girardi said.

Esmil Rogers, starting for Triple-A Buffalo when claimed on waivers last Thursday, was 2-2 in 14 games (seven starts). His last six games were starts and in the final three the right-hander worked six innings, 7²/₃ , and six innings.

Since joining the Yankees, Rogers worked two games in relief. He did not pitch Wednesday, and if he doesn’t pitch Thursday, he is a strong candidate to get the start Friday.

Wednesday was team photo day and CC Sabathia was on hand with a full beard. Sabathia was scheduled to see Dr. Chris Ahmad on Wednesday night and is anticipating another stem-cell treatment on his right knee in about two weeks.

“They will Photoshop that out,’’ said Sabathia, knowing full well the Yankees’ no-facial-hair-below-the-lip policy. When Sabathia ditches the crutches, he will be on the bench for games and clean-shaven. He can’t get to the bench these days because of the crutches.

A.J. Preller was named the Padres’ general manager Wednesday. Preller, the Rangers’ senior director of player personnel, was hired over Yankees assistant GM Billy Eppler.

Joba Chamberlain has known Betances since they were Yankees minor leaguers and like everybody else in baseball, has been awed by Betances’ season.

“I grew up with Dellin,” Chamberlain said. “He got drafted the year before me. And we have the same agent, so I got to know him on a personal level.

“He’s always had the stuff. He was a starter and went through his bumps and bruises and came up again last year and didn’t do great but we knew he threw hard, knew he had great stuff.

“I’d see him in spring training, and I talked to him a couple times just to know he had a chance and that’s all he needed to know that hey we’re going to give you the ball it’s up to you and I think he’s matured a lot. Obviously it shows.’’

With Betances logging a bullpen-high 67 ²/₃ innings in 50 games, Girardi is keeping an eye on the arm that has produced 100-mph fastballs lately.

“We watch it. I don’t think we’ve overworked him, but we still have to pay attention to what we do. That’s why I took him out [Tuesday],’’ Girardi said of the right-hander who had 100 strikeouts and is holding opponents to a .129 average.

Additional reporting by Fred Kerber and Larry Brooks