Harbaugh also refutes reports earlier this week that he already has told Smith and Colin Kaepernick that Kaepernick will continue as the team's starter after making his first NFL start during Monday's rout of the Chicago Bears.
The coach indicates his stance on the quarterback situation is unlikely to change before the 49ers (7-2-1) meet the Saints (5-5) in a rematch of last year's NFC divisional playoff game won 36-32 by San Francisco.
"We could set our watch here for another 15 minutes and you could keep asking questions and the answers will still be the same," Harbaugh said Friday. "We feel like there's no competitive advantage for us to release that information. We just do not get into what the role's going to be, how we're going to use them, and the specifics of that. It's unorthodox. So be it. That's the way we are going to go about it."
Smith practiced again in a black jersey Friday, as he has all week, and Harbaugh said Smith has gone several days without exhibiting any concussion-like symptoms.
"Alex went through his final test today and will be cleared tomorrow, if tomorrow again there are no symptoms," Harbaugh said. "He hasn't had any symptoms since Tuesday, so that's a real positive."
Kaepernick and Smith did not speak Friday with reporters. A decision will be made Saturday regarding Smith's status for the Saints game.
The rule that negated using video replay to confirm a Houston Texans touchdown "may be too harsh" and will be re-examined immediately, NFL director of football operations Ray Anderson said Friday.
Anderson, also co-chairman of the competition committee that suggests rules changes to the owners, said a change could come this year. The NFL traditionally resists changing rules during a season.
Anderson added the NFL is not bound by past events when a rule is proved to have loopholes, and that a 15-yard penalty for throwing the challenge flag on a play that is automatically reviewed might be enough. For now, throwing the challenge flag also eliminates the use of replay. All scoring plays otherwise are reviewed.
Justin Forsett's third-quarter 81-yard run in the Texans' 34-31 overtime victory at Detroit on Thursday initially was ruled a touchdown, although replays clearly showed his knee and elbow touched the turf when he was hit by Lions defenders. Detroit coach Jim Schwartz challenged, resulting in a 15-yard unsportsmanlike conduct penalty and the negated use of video replay.
"I overreacted," Schwartz acknowledged. "And I cost us."
Around the league
Chargers • San Diego placed left tackle Jared Gaither on injured reserve Friday, ending an unproductive season for a player expected to shore up a shaky offensive line.
Steelers • For the first time in seven weeks, Troy Polamalu was on the practice field. The safety has played in only five quarters this season due to a strained right calf.
Vikings • Minnesota will likely be without WR Percy Harvin again this weekend because of his sprained left ankle.
Jets • Rex Ryan insists that Tim Tebow "100 percent" could have played in the New York's lopsided loss to New England, despite the backup quarterback having two broken ribs. Tebow was active for the game, but Ryan kept him on the sideline and intended to use him only if the Jets "absolutely have to."
Week 12 schedule
• Houston 34, Detroit 31 (OT)
• Washington 38, Dallas 31
• New England 49, N.Y. Jets 19
• Denver at Kansas City, 11 a.m., Ch. 2
• Minnesota at Chicago, 11 a.m., Ch. 13
• Oakland at Cincinnati, 11 a.m.
• Pittsburgh at Cleveland, 11 a.m.
• Buffalo at Indianapolis, 11 a.m.
• Tennessee at Jacksonville, 11 a.m.
• Atlanta at Tampa Bay, 11 a.m.
• Seattle at Miami, 11 a.m.
• Baltimore at San Diego, 2:05 p.m.
• St. Louis at Arizona, 2:25 p.m.
• San Francisco at New Orleans, 2:25 p.m., Ch. 13
• Green Bay at N.Y. Giants,6:20 p.m., Ch. 5
• Carolina at Philadelphia,6:30 p.m., ESPN