CLEVELAND — The Browns are down another starting quarterback.

Josh McCown will miss at least one game with a “deep sprain” in his left shoulder, forcing Cleveland to play rookie Cody Kessler this week — the team’s third starting quarterback in three games this season and 26th since 1999.

McCown stayed in Sunday’s 25-20 loss to Baltimore despite getting hurt in the first quarter and taking several hard shots.

The 37-year-old was filling in for Robert Griffin III, who broke a bone in his left shoulder in the season opener and will miss at least eight games — and maybe more.

Browns coach Hue Jackson was evasive about the extent of McCown’s injury. He said the 37-year-old will be evaluated on a week-to-week basis.

In the meantime, Kessler, a third-round pick from USC, will start against the Dolphins. Jackson said the team will look to add a veteran to its roster, but the job for now belongs to Kessler, who struggled during training camp and the exhibition season.

“We’ll find out a lot about him this weekend,” Jackson said.

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The Browns are the first team since the 2008 Kansas City Chiefs to start three QBs in the first three weeks.

Kessler was a surprise pick by the Browns, who also lost starting center Cam Erving (bruised lung) and rookie defensive end Carl Nassib (broken hand) against the Ravens.

Erving was released from the hospital following an overnight stay. Nassib will undergo surgery, but Jackson said it’s possible the former Penn State standout may be able to play in the future with a protective cast.

With Erving out, John Greco will slide over from right guard to center. There’s also a chance the Browns will add a veteran center.

McCown became emotional in his postgame news conference while addressing his reasons for not coming out of the game. McCown’s two sons, who are both playing quarterback in middle school, were in attendance at FirstEnergy Stadium.

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The 14-year veteran landed hard several times on his shoulder and he couldn’t lift his left arm as he entered the trainer’s room following his news conference. The pained expression on his face hinted at the severity of his injury.

Kessler is next on the depth chart. He twice warmed up on the sideline Sunday, but McCown stayed on the field, exhibiting toughness that wasn’t lost on his coaches or teammates.

When the Browns selected Kessler in the draft, Jackson tried to ease any anxiety Cleveland fans had over the pick by saying, “trust me” about taking Kessler.

On Sunday, Kessler said he was set to take over for McCown if he was asked.

“It’s a physical game and you always have to be ready,” he said. “It’s kind of a next-man-up mentality and I prepared as hard as I could all week. I didn’t have any nervousness or anxiousness, I was ready to go.

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“Just because of my prep all week and learning from Josh and listening to what he did, watching the reps he did and getting more reps in practice. I felt ready to go. If that did happen, I had the mindset of going in as the starter.”