The Giants announced that rookie catcher Daniel Susac has a fractured patella (kneecap) in his left knee. He’ll meet with doctors this evening to determine a treatment plan.

San Francisco will obviously place Susac on the 10-day injured list shortly. They’re going to need a new catcher to pair with Drew Cavanaugh. With Jesus Rodriguez already on the IL due to right elbow neuritis, they’ll need to select someone else onto the 40-man roster before tonight’s game against the Astros. The Giants already have a vacancy on the 40-man, so there won’t need to be any further moves beyond Susac’s IL placement.

They may wind up making multiple roster moves to address the backup catcher role. No other catcher currently in the organization has any major league experience. Alex Pavlovic of NBC Sports Bay Area reports that the Giants will use Cavanaugh as the starter.

According to Pavlovic, the Giants will select a short-term backup tonight but are exploring the market for a more experienced option for the remainder of the season. Former Giants Chadwick Tromp and Andrew Knizner recently hit free agency, as a couple speculative options. Another possibility would be to try to grab Willie MacIver (designated for assignment by Toronto this afternoon) off waivers.

In the short term, they’ll likely need to call upon an organizational depth type from Triple-A Sacramento. Zach Morgan and Adrián Sugastey are the catchers on the River Cats’ roster. The 23-year-old Sugastey has spent more time this year in Double-A and was only bumped up coming out of the All-Star Break. Morgan, 26, is a former seventh-round pick who’s hitting .231/.323/.325 in 28 games this year. Susan Slusser of The San Francisco Chronicle reports that he’s meeting the big league club in San Francisco, though it’s not clear if he’ll formally be called up or join the taxi squad.

Susac took over as San Francisco’s starting catcher. His hot start as a Rule 5 pick played at least some role in the Giants’ willingness to trade Patrick Bailey to Cleveland in early May. Susac hasn’t hit nearly as well since coming back from elbow neuritis that shelved him a few weeks into the season. He also missed a couple weeks with a lower back strain leading up to the All-Star Break. He’s hitting .243/.289/.375 with a trio of home runs across his first 161 big league plate appearances. Susac has graded very highly defensively, though, throwing out a third of baserunners with good framing numbers.

Cavanaugh was called up in late June when Susac went down with the back issue. He has appeared in 26 games and stepped to the plate 73 times. He’s batting .241 with a .362 on-base percentage thanks to 11 walks but has only managed one extra-base hit (a double). Cavanaugh’s defense has been an issue, as he has committed four passed balls and three throwing errors in fewer than 200 innings. He has thrown out five of 26 baserunners.