The San Francisco 49ers put quarterback Alex Smith on injured reserve with a shoulder injury, probably ending the former No. 1 draft pick’s four-year career with the team.

Smith had surgery on his right shoulder in December, but appeared to be at full strength in training camp. He lost his starting job to journeyman J.T. O’Sullivan in camp, and Smith then felt a painful new injury in his shoulder during practice before last week’s season opener.

The San Francisco 49ers added quarterback Alex Smith to their injury report Saturday, listing him as doubtful for Sunday’s game against Arizona with another problem in his surgically repaired right shoulder.

Shaun Hill will be the backup against the Cardinals.

The 49ers didn’t specify what was wrong with Smith, only saying the injury occurred without contact during practice Friday. Smith, the former No. 1 overall draft pick, was expected to back up J.T.

Mike Martz and Alex Smith have something to prove as they team up to help turn the 49ers’ fortunes around.