LONDON -- Quarterback Troy Smith could leave England with his ultimate souvenir: the 49ers' permanent starting job.
Nobody on the team has said as much, but the door looks open for Smith to stake his claim. Alex Smith already was being evaluated on a week-to-week basis, while David Carr's failed audition lasted all of 13 passes.
Enter Troy Smith, who can put a stranglehold on the job even if he doesn't put up dazzling statistics. All he has to do is win. A victory over the Denver Broncos would separate him from the rest of the struggling pack.
Can Troy Smith do it? It's a mystery worthy of Scotland Yard. He hasn't started a game since 2007 and didn't sign with the 49ers until Sept. 6.
He has barely played, not even in practice. Smith arrived less than a week before the season opener and assumed the role of third-stringer. His only action has come with the occasional scout-team snaps.
It took an injury to Alex Smith (separated shoulder) and an apparent distrust of Carr (a 23.6 passer rating last week) to shoot Troy Smith up the depth chart.
He looked OK during the practices in London, throwing a nice spiral and showing there is still some bounce in his 26-year-old step. But coach Mike Singletary declined to offer a review of those sessions, saying that the only way to measure a quarterback is to see how he responds to the glare of game-day pressure.
Even offensive coordinator Mike Johnson isn't sure what he's going to get. He spent the week getting a crash course on Smith's strengths and weaknesses so he would know what plays to call against the Broncos.
Smith, meanwhile, greeted the challenge with a Yoda-like calm.
"It's not about trying to do," he said. "I have to do what I have to do."
Smith, a former Ohio State standout, was the 2006 Heisman Trophy winner, blowing away runner-up Darren McFadden (who rushed for 165 yards and three touchdowns against this Broncos defense last week).
At his best, Smith operates as a dual threat -- a passer capable of breaking off a long rush. In his 14 career NFL games, he has 29 rushes for 109 yards with two touchdowns.
But Johnson said he had no plans to factor Smith's speed into his X's and O's. "He is definitely a good athlete, but that's not something that we're designing and putting together," Johnson said. "We're not putting together an offense where Troy Smith is going to run the ball. You know we're not trying to do that."
If Smith can find a way to win -- whether it's with his arm or with his legs -- he could ensure that he doesn't go another three years between starts. If he can rescue the 49ers from the abyss, he could keep the job even if Alex Smith heals up after the 49ers' bye week.
"Well, I'm not thinking about that," Troy Smith said. "We came over here with one job and one mindset, and that's getting out of here with a win. Anything else is not in my thought process."
Singletary has not opened the door for a new quarterback, but the 49ers are desperate for someone who can avoid mistakes and create a sense of rhythm on offense.
Troy Smith has never thrown for more than 199 yards in an NFL game, but Marino-esque numbers are not high on Singletary's list of requirements. He just wants someone who can save them from flying back to the States with a 1-7 record.
On the day that Singletary announced Smith as the coach's quarterback against Denver, he vowed, again, that the 49ers were on the verge of turning things around. He said so in answer to a question from a member of the British press, who wondered if Singletary dreamed of getting the 49ers back to the glory days of Jerry Rice and Joe Montana.
"The one thing I don't do is spend much time thinking about what was," Singletary replied. "I spend a lot of time thinking about the possibilities ahead of us. I talked to the team this morning, and one of the things that I told them -- and I will tell you -- is that this is our finest hour as a team, and as a staff."
For more on the 49ers, see Daniel Brown's Hot Read blog at blogs.mercurynews.com/49ers.