With each new day, Yankees first baseman Greg Bird is building up confidence in his ability to play the corner bag.

No, not that corner bag.

The 24-year-old was seen taking grounders at third base on Thursday at the George M. Steinbrenner Field complex, according to a photo taken by WFAN’s Sweeny Murti.

Following Mark Teixeira’s retirement, the starting first base gig is open for the first time in eight seasons. The competition was supposed to include three names, but Tyler Austin’s broken foot has taken him out of the running this spring. In the meantime, Bird opposes 30-year-old slugger Chris Carter, who was signed as an insurance player this winter on a one-year, $3.5 million deal.

The Yankees have been known for tinkering with players and their positions. Recently, manager Joe Girardi has moved shortstop prospects Gleyber Torres and Jorge Mateo around the infield, with Mateo even taking flyballs in center. The possibility of second baseman Starlin Castro moving to third has also been discussed in the past.

As long as Chase Headley stays healthy, he will assume third base duties, but the image of Bird wetting his beak at third shouldn’t come as a surprise, considering Girardi’s spring ingenuity.

“We saw it for a two-month period,” Girardi told the Daily News of Bird’s ability to produce runs. “And I know there will be some adjustments and he’s coming off of injury, but I’m not going to get so caught up in the power numbers. If he’s who we think he is, he’s gonna be plenty good.”

Bird’s major league experience is only 46 games old, as he missed all of 2016 recovering from shoulder surgery. But he did raise some eyebrows in the Bronx after hitting 11 home runs with 31 RBI in 2015.

“I have to prove that I’m healthy and get used to playing again, so I have enough on my plate,” Bird told Murti on Tuesday. “I’m fighting to prove that I’m healthy and I can play. I’m not fighting against anyone in particular. I’m just trying to play, and play at a high level again and get better every day and become the best possible player that I can be.”