Smith repeatedly was booed by the Candlestick Park crowd last season as San Francisco struggled on offense, leading to a 6-10 record. Alex Smith was replaced by Troy Smith for five games from Oct. 31 through Dec. 5, initially after he separated his non-throwing shoulder during an Oct. 24 game at Carolina. In the season finale against the Arizona Cardinals, Alex Smith went 15-of-29 passing for 276 yards and two touchdowns, but he was booed after every incompletion, according to The Bee.
"Well, the question is, do you have baby deer skin or skin like an armadillo?," Harbaugh told the newspaper Tuesday. "That's where the rubber meets the road there. If someone doesn't like me or doesn't cheer loud for me -- is he going to be deep and emotionally scarred by that? I mean, most true competitors, most men like that would take offense to somebody inferring that about him.
"He's a tough son of a gun," Harbaugh added. "I watched four really solid years of every snap the guy took -- getting hit in the pocket, picking himself back up, playing under adversity, fierce competitor. I don't think (booing) will affect the guy."
Smith, who became an unrestricted free agent Feb. 4 and hasn't signed a deal, has participated in weightlifting sessions with teammates. He can't sign with any team until a new collective bargaining agreement is reached.
When asked about the 49ers' contract offer Tuesday, Harbaugh could only say "the NFL does not want us to comment on contract situations."
The Bee's attempts to reach Smith for comment were unsuccessful.
The Associated Press contributed to this report.