SANTA CLARA – Whatever you do, don't ask 49ers coach Jim Harbaugh any more questions about Kyle Williams' readiness as a punt returner.

Williams is in the spotlight heading into Sunday's game in Green Bay because the team's primary return man, Ted Ginn, is unlikely to play with an ankle sprain suffered Aug. 26. Williams had those two memorable miscues on punts while substituting for Ginn in the 49ers' last meaningful outing, their Jan. 22 loss to the New York Giants in the NFC Championship Game.

Early in Friday's news conference, Harbaugh said, "We've always been extremely confident in Kyle as a returner, both as punt returner and a kickoff returner."

That was as far as he was willing to go on the subject. When a reporter revisited the topic at the end of the session, Harbaugh shut him down.

"We don't, we don't … why'd you bring that up?" Harbaugh asked. "Why would we be talking about that? When is enough enough?"

The reporter followed up by asking Harbaugh if he felt compelled to give Williams encouragement – an "attaboy" – going into the game.

"I should ask you, why did you bring that up?" Harbaugh said while staring down the reporter. "Why do you continue to ask that question? What is the reasoning?"

Williams was not available for interviews. After the exhibition game in Denver – the one in which Ginn was hurt – Williams said he was eager to handle punt returns if Ginn couldn't play.

"My confidence level is always at 100 percent," Williams said. "I don't feel uncomfortable at all back there."

Special-teams coach Brad Seely, meanwhile, spoke at length about Williams' ability to return punts, saying he had "no worries" about him in Green Bay and that he encouraged Williams to be aggressive.

"He likes to attack it a little bit more," Seely said. "I think you see that maybe a little bit more out of him than you will out of other guys. I think it's because he has an extreme amount of confidence in his ability to catch the ball. And he's a really fine catcher."

Is Seely comfortable with Williams sprinting forward to catch short punts?

"Yeah," Seely said. "That's the way we want him to go play. We want him to go after it. Again, what we always say is, 'I'm not out there playing – it's your (the returner's) play. Make a good one.' "

Dogged blockers – The mark of a good lead blocker? You don't necessarily have to see the block to know that it was effective.

When it comes to 49ers converted fullback Will Tukuafu, the sound of his blocks has been convincing enough.

"He's crushing people," said defensive end Justin Smith, who was on the sideline when Tukuafu delivered a big block against the San Diego Chargers in the exhibition season finale.

"You can hear it," Smith said. "It's pretty impressive. I know I wouldn't want to take on a 295-pound fullback. I'm sure Green Bay's hoping he's just a gimmick and (we) won't use him as much because he's put some pretty impressive stuff on tape."

Tukuafu is one of two defensive ends the 49ers have converted into two-way players. The other is part-time tight end Demarcus Dobbs, who gave himself and Tukuafu – they were roommates during training camp – a nickname.

"I tell them I'm a mutt," Dobbs said. "I'm just a mutt. I do all types of different things – all types of breeds. I just tell them I'm a defensive lineman, but I do pretty much everything. … I do take pride in being a mutt.

"There aren't many mutts around this league. Mutts are always a better dog, anyway."

Injuries – Ginn and Brandon Jacobs (knee) did not practice this week and are listed as questionable; both traveled to Green Bay.

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