San Francisco 49ers head coach Mike Nolan and offensive coordinator Mike Martz are heaping praise on quarterback J.T. O’Sullivan– and it’s hard not to read their praise as criticism of Alex Smith.

“He has an excellent arm, no question about it,” Martz said of O’Sullivan. “He’s very accurate, very quick with the ball. He just needs to play. He needs to develop.”

O’Sullivan was widely expected to be the third-string quarterback behind both the winner and the loser of the battle between Smith and Shaun Hill. But the 49ers say that’s not the case; O’Sullivan has a real shot at beating both of them.

“It’s a three-man race, not just two,” Nolan said.

In 2007, the 49ers’ passing game looked horrible all season, with both Smith and Trent Dilfer running the show. But then in December, Hill started two games and got significant playing time in a third, and all of a sudden the 49ers’ offense looked competent.

That Hill, who had never thrown an NFL pass until last season, would play so much better than Smith was one very bad sign for Smith, the 2005 No. 1 overall pick. The coaches’ praise for O’Sullivan is another.