Alex Smith looks forlorn as he watches Sunday's opener from the 49ers sideline. (Paul Sakuma/Associated Press)

Alex Smith's season is over with another shoulder injury, and the high-priced quarterback's brief career with the San Francisco 49ers is probably finished as well.

The Niners put Smith on injured reserve Wednesday with a broken bone in his right shoulder.

The No. 1 overall pick in the 2005 NFL draft probably will require more surgery on the joint that limited him to seven games last season.

Niners head coach Mike Nolan claimed to know little about the injury that ended his former franchise quarterback's fourth NFL campaign before Smith even played in a regular-season game this fall.

Smith's teammates expressed more concern than their gruff coach over his latest injury, which popped up during the club's final practice before last week's season opener.

"I feel sorry for him," Niners running back Frank Gore said. "He was a great teammate and worked hard.

I just hope the best for him. Hope he gets well."

After paying Smith more than $31 million US during his four years with the Niners, the bleak realities of NFL salary cap life mean the club is likely to release him before next season.

Niners general manager Scot McCloughan said last week that San Francisco cannot risk paying $9 million US in base salary to a backup quarterback in 2009.

Smith lost his starting job to journeyman J.T. O'Sullivan in training camp.

"I'm not going to answer any hypothetical questions about the future," said Nolan, who had an embarrassing public spat with Smith last year over the severity of the quarterback's shoulder injury.

"We will cross that bridge when we get there. My focus right now is on [Sunday's opponent] Seattle."

'He wasn't really ready to go'

Smith refused to comment after practice, and didn't respond to an additional request for comment Wednesday afternoon.

Smith had surgery on his shoulder in December to repair three torn ligaments, the product of a separated shoulder from a game in late September 2007.

He attempted to play through pain after the injury, but obviously struggled in all three games, culminating in an awful effort in a 24-0 loss at Seattle.

"I thought he wasn't ready to go," said Seahawks linebacker Julian Peterson, Smith's former teammate in San Francisco.

"I thought he just tried to tough it out for the team, and it really wasn't a smart move for the team and for himself. He tried to do it for the team and wasn't really ready."

After several months of rehabilitation, Smith appeared to be at full strength in training camp, despite losing his job to O'Sullivan, who was quicker to pick up new offensive co-ordinator Mike Martz's system.

But Smith experienced severe pain in his shoulder last Friday while making a long throw during practice, and subsequent tests found a significant problem.

'Injuries hampered him'

Noted sports surgeon Dr. James Andrews of Birmingham, Ala., who performed Smith's last surgery, confirmed the team's diagnosis of a broken bone in Smith's shoulder, though the quarterback and the team still don't know how it happened.

The Niners signed 38-year-old quarterback Jamie Martin, a veteran of Martz's system who was out of football, to back up O'Sullivan and Shaun Hill.

"He worked so hard to get back and, then, to have this happen to him now is so unfortunate," said Hill, who backed up Smith, as did Trent Dilfer, the past two seasons.

"Obviously, it's not an easy thing for him. Even last year, Trent and I were excited for what he was going to do.

"I don't think he's a bust at all. Injuries hampered him."

Smith passed for 4,679 yards with 31 interceptions and 19 touchdowns in his first three seasons with the Niners, who selected the former Utah star with the first pick of Nolan's regime.

He left the Utes one year early to capitalize on the excitement of their undefeated season under head coach Urban Meyer, and he was rewarded with $24 million US in guaranteed money as the No. 1 pick in a notoriously weak draft with no clear-cut top selections.

Smith went 11-19 as a starter, never finding a consistent NFL groove while playing for four offensive co-ordinators in four seasons and throwing to one of the league's worst collections of receivers.

San Francisco's offence finished last in the NFL in 2005 and 2007, with Smith receiving a share of the blame, even though he played only part of his rookie season and missed most of 10 games last year.

In 2006, his only full season as a starter, Smith took every snap and posted respectable numbers for offensive co-ordinator Norv Turner while the Niners went 7-9.

Turner then left to become head coach of the San Diego Chargers.