SANTA CLARA, Calif. — The 49ers must reduce their roster to 53 players by Saturday afternoon, but it sounded Thursday as if Mike Singletary didn’t need any extra time to decide.

Singletary said he had a “very good idea” about the composition of his final roster heading into Friday’s exhibition finale against San Diego. Asked to clarify, he later said there were “one or two” positions that might be settled against the Chargers.
Those one or two positions? One of them likely is for the third tight end spot where J.J. Finley, an undrafted free agent last season, is trying to hold off sixth-round pick Bear Pascoe from Fresno State. Finley received more playing time than Pascoe on Saturday against Dallas and made a 19-yard reception that set up the 49ers’ first touchdown. Singletary said this week the two were even heading into the final game.
The final cornerback spot also is up in the air. The 49ers recently signed Eric Green, who forced a fumble late in the Cowboys game. Green is a better cover cornerback than his competition, Marcus Hudson. However, Hudson is a proven contributor on special teams who made a nice triumvirate with Michael Robinson and Jeff Ulbrich last year on coverage teams.
The 49ers also promise to begin the season with five receivers, not including holdout Michael Crabtree. Isaac Bruce, Josh Morgan, Arnaz Battle and Brandon Jones are safe bets to make the squad, leaving Micheal Spurlock, Jason Hill and Dominique Zeigler to vie for the last spot.
The 49ers also have to decide whether to keep four tailbacks — notably rookie Kory Sheets — on the roster.
Sheets, who ranks sixth in the NFL in rushing yards this exhibition season, promises to see plenty of action. Bruce and starting tailback Frank Gore won’t play at all while the other starters, including rookie tailback Glen Coffee, will play only one or two series. Shaun Hill will start the game at quarterback, but he quickly will give way to rookie Nate Davis.
San Diego native Alex Smith practiced only partially this week with a sprained thumb and will not play, Singletary said.