When Triston Casas went down with a season-ending injury, Romy Gonzalez shifted from his usual role as a utility player to become Boston’s new starting first baseman. But soon after taking over he suffered an injury on the base paths of his own and has been out since May 8 with a left quad contusion.

Originally the hope was that Gonzalez wouldn’t miss much time, but now it appears he could be out longer than anticipated.

“He’s not bouncing back the way we wanted,” Red Sox manager Alex Cora said on Wednesday. “When he started running he felt it again, so he’s going to take longer than expected.”

With Casas and Gonzalez both on the shelf, the Red Sox have tried to get by with Abraham Toro and Nick Sogard manning the position. Toro has started five games at first base since Gonzalez’s injury and Sogard has now started eight, including each of the three games against the Mets.

Toro is 4 for 21 (.190) with a double and a home run in those games, and Sogard entered Wednesday 6 for 27 (.222) with one double.

Looking for another option, the Red Sox have begun introducing rookie Kristian Campbell to first base, a position he has never played professionally. Campbell has done regular pregame drills at first base since Friday but has not progressed to a point where Cora says he’s comfortable playing him there just yet.

There is also no indication the Red Sox will shift Rafael Devers to first, something the slugger has come out vocally against.

In addition to Gonzalez, Cora provided several other injury updates prior to first pitch.

Right-hander Richard Fitts (right pectoral strain) is scheduled to begin a rehab assignment in Worcester on Thursday, though with rain in the forecast that could be pushed back. Right-hander Kutter Crawford (right patellar tendinopathy) is scheduled to throw three innings of live batting practice on either Thursday or Friday, and right-hander Tanner Houck (right flexor pronator strain) is due to resume throwing by the end of the week after being shut down following his most recent outing on May 12.

Masataka Yoshida (right shoulder labral repair) also resumed his throwing program on Wednesday, but the outfielder is back to square one starting at 60 feet after previously working his way up to 120.

Extra innings

After being ejected on Tuesday night, Cora said he spoke with Mike Hill, MLB’s senior vice president of on-field operations. Asked if he’d received a fine, Cora said “we’re good,” adding “he called me, asked me about the graduation and how are the kids.” … Triston Casas has been back at Fenway Park over the past few days. The first baseman is out for the season after suffering a ruptured patellar tendon but Cora said Casas has been in good spirits. … With rain in the forecast there is concern around the team that Thursday’s series opener against Baltimore could be postponed and a doubleheader played on Friday. Asked about the possibility, Cora said he hasn’t heard anything either way, adding “let’s play today and then they’ll decide what we do tomorrow.”