HOUSTON -- Astros closer Roberto Osuna, who abruptly left Saturday’s game against the Angels in Anaheim with an arm injury, will need season-ending Tommy John surgery, according to a report by TV station KRIV-TV in Houston on Tuesday. The report said Osuna is seeking a second opinion.

The Astros have not confirmed the report, but manager Dusty Baker, during an interview on 790 AM in Houston on Tuesday, painted a grim picture of Osuna’s diagnosis.

“It doesn’t look real good, actually,” Baker said from Arizona, where the Astros open a three-game series at the D-backs on Tuesday. “He went and had an MRI yesterday. He’s in our prayers and in our thoughts. The reality is it’s probably not really good news.”

Osuna, making only his fourth appearance of the season, called trainers to mound after throwing a pitch in the ninth inning Saturday and was placed on the injured list Sunday. The Astros lost Justin Verlander to a forearm strain after one start and shut him down for two weeks, and pitchers José Urquidy, Chris Devenski, Austin Pruitt and Brad Peacock are also in the IL.

Osuna posted a 2.63 ERA with an American League-high 38 saves last season for Houston, one year after the club acquired him from Toronto.

Nine rookie pitchers have appeared in a game through the first nine contests of the season, with seven of those -- Blake Taylor, Cristian Javier, Brandon Bielak, Andre Scrubb, Enoli Paredes, Nivaldo Rodriguez and Brandon Bailey -- making their big league debuts. The other two rookies are Cy Sneed and Bryan Abreu, who made their debuts last year.

To replace Osuna, the Astros added right-hander Humberto Castellanos to the Major League roster from the taxi squad Sunday. Castellanos and Carlos Sanabria, added from the taxi squad Saturday for Devenski, have yet to make their debuts.