KISSIMMEE, Fla. -- Astros backup catcher Max Stassi flew to Houston to be examined by a hand specialist after suffering an injury to the hamate bone in his left hand, manager A.J. Hinch said Sunday. Hinch said Stassi would see a doctor on Monday and is expected back in camp in a couple of days.

Stassi, 25, has the inside track for the backup catcher job this year behind starter Jason Castro following the offseason trade of Hank Conger to the Rays. Hinch said Stassi had been bothered by the injury for the past few days and had an X-ray, the results of which weren't yet known.

Hinch said Stassi's injury bothered him more swinging the bat than catching, considering the hamate bone is outside of where Stassi wears his catcher's mitt.

"I don't like the fact he's not feeling great and he's got to go back to see a specialist," Hinch said. "In my shoes, that's never a positive step until you hear good news back. We'll see how it goes. For us to send him back to Houston, it means we obviously have concern based on the initial diagnosis. We'll see where it takes us."

The Astros are unproven at catcher after Castro. Stassi has appeared in just 21 games in the Majors over the last three seasons with the Astros, hitting .357 (15-for-42) with a homer. Tyler Heineman, Roberto Pena and Alfredo Gonzalez are the only other three catchers in camp.

They had planned on designated hitter Evan Gattis getting back behind the plate this spring, but he had hernia surgery a month ago and is just now returning to drills. Still, Hinch said the Astros have some good options behind the plate.

Pena played all of last season at Double-A Corpus Christi and hit .237, but is considered an elite defender. Gonzalez, who hit .321 across three Minor League levels last year (topping out at Double-A), has the best arm of any position player in camp. Heineman, a switch-hitter who got his feet wet at Triple-A last year, has a well-rounded approach.

"Luckily, we have some guys who are equipped to handle things, especially on the defensive side," Hinch said. "Pena and Heineman and Gonzo are all very equipped defensively. None of them have been tested at the upper levels offensively. We have catching depth. It may be unproven and untested, but I'm very comfortable with the guys we have being options moving forward so we'll see how things progress. We have some guys who have done some things in the Minor Leagues defensively."



Reliever Luke Gregerson is expected to make his way into a game -- Grapefruit League or Minor League -- on Wednesday or Thursday after throwing live batting practice in Kissimmee on Saturday with no problems. Gregerson was slowed at the start of camp with a strained left oblique.



Gattis, who had sports hernia surgery a month ago, participated in baserunning drills on Monday and took batting practice once again. "We're loading him with more and more activity every day and his response is pretty good," Hinch said. "He hit it pretty hard yesterday and felt good today."