LAKE BUENA VISTA, Fla. — What had been a mostly healthy camp for the Yankees ended with the unmistakable thud of ball on skin and the team possibly without two-thirds of their much heralded back end of the bullpen.

Andrew Miller was forced out of Wednesday’s game when he was drilled by a line drive hit by the Braves’ Willians Astudillo in the seventh inning.

Miller was sent back to Tampa for X-rays, which came back negative, the Yankees announced early Wednesday evening. However, a CT-scan taken later revealed a chip fracture in the wrist. Miller will visit with a hand specialist to determine the next step. It was not immediately known whether Miller will have to start the season on the disabled list, though it seems likely.

With closer Aroldis Chapman suspended for the first month of the season, Miller was in line to fill that role, one he occupied last season when and went 36-for-38 in saves with a 2.04 ERA.

GM Brian Cashman didn’t downplay the impact of possibly losing Miller for a long period of time but did point out the Yankees survived without the 30-year-old lefthander for 25 games from June 10-July 8 after he sustained a flexor strain in his left forearm.

“You want to [have] everybody at times,” Cashman said. “It’s just not how the game works.”

Dellin Betances, likely to step in as closer if Miller is not able to start the season, said he talked with Miller before he left and exchanged text messages later.

“I think he’ll be all right, to be honest,” Betances said. “It’s his glove-hand side, so hopefully he’ll be good. Any time you get a line drive, it’s not going to feel good. When he was in here talking to me he was all right, just hope nothing happens [with the tests].”

Astudillo, pinch hitting for A.J. Pierzynski, led off the seventh against Miller and sent a liner, on the first pitch he saw, up the middle that nailed the pitcher on the outside of his wrist.

Miller immediately started walking off the mound toward the dugout, intercepted on his way there by Joe Girardi and a Yankees trainer. Girardi said he didn’t draw any conclusions from Miller’s reaction, which included him throwing his glove into the dugout from the top step.

“It [his reaction] doesn’t say that there’s something definitely broken, but it said it really hurt,” Girardi said. The manager said earlier he observed a “substantial bruise” on the pitcher’s wrist.

Miller was seen by a Braves doctor before leaving for Tampa.

“He saw the doctor, he did all the stuff, he could move his fingers and do all that, so I felt better about it,” Girardi said. “But it was still really purple.”

The bullpen, rock solid and injury-free pretty much all spring, was thrown further into disarray when righthander Bryan Mitchell, brilliant throughout the exhibition season and named to the 25-man roster the day before, left in the eighth inning after injuring his big left toe. Mitchell was slated for an MRI later Wednesday. In the Champion Stadium clubhouse Cashman said the initial diagnosis was the 24-year-old Mitchell had a “sprained big toe.”

“I honestly don’t know what to feel right now,” said Mitchell, who pitched to a 0.57 ERA this spring to win the a bullpen job. “I’m just trying to stay positive. Hopefully when I wake up tomorrow it feels 10 times better than it does.”

Girardi had hoped to have all of his bullpen slots decided by Thursday, as righthanders Kirby Yates, Johnny Barbato and Luis Cessa were the final three in camp fighting for two open spots. Now, those decisions may have to be pushed back as the Yankees wait and see on the severity of the injuries to Miller and Mitchell.

“It’s substantial because the one thing we’ve talked about is we liked our bullpen and the length that it has,” Girardi said of the possibility of losing Miller for an extended time. “You lose one, someone has to step up. You lose two and you’re asking a lot. But we’ll have to figure it out if it comes to fruition.”