Bucs Head Coach Dirk Koetter announced on Monday evening that quarterback Jameis Winston had suffered an AC joint sprain in his right shoulder during the first quarter of the Bucs' 38-33 loss at Arizona on Sunday.

An MRI performed on Winston on Monday morning revealed the injury.

"Jameis is day-to-day right now," said Koetter. "When we get back to practicing on Wednesday, Jameis will not be doing any throwing. He probably will do little throwing during the week."

However, Winston has not been ruled out for Sunday's road game at Buffalo.

"Its a good thing he isn't ruled out as we stand here today," said Koetter.

The Bucs coach also stressed that the injury would not worsen if Winston tried to play through the pain this weekend.

"We will wait and see, man, Jameis is such a competitor," said offensive lineman Evan Smith. "He is a fighter and I would not be surprised (if he played)."

After Sunday's loss Winston said he did not think this injury would keep him out of any games, saying he would be playing again "soon."

Backup quarterback Ryan Fitzpatrick will take the first team reps on Wednesday and Ryan Griffin, eligible to practice as he returns from his own shoulder injury suffered during the preseason, will run the scout team.

Fitzpatrick played nearly three quarters on Sunday, throwing 290 yards, three touchdowns and two interceptions. He nearly led a full comeback for the Bucs, who were down 31-0 at one point against the Cardinals.

"Its a blessing to have Fitzpatrick and the drop off is not too severe," said Bucs defensive end Noah Spence. "We want Jameis to get back, but luckily our concerns would lessen (because of Fitzpartick)." 

"Look what Ryan did in less than three quarters. If he has to go start, we have all the confidence in the world with him out there."

It would also be a chance for Fitzpatrick to play a former team he once started for in Buffalo. Fitzpatrick played for the Bills from 2009-2012 and had 55 touchdowns.

"He has 126 starts and that is big for us to have," said Koetter. "It's why we went out and got him in the offseason to back up Jameis."