Sanchez takes all the first-unit snaps

USC quarterback Mark Sanchez has not been told officially that he will make his second start on Saturday against Notre Dame, but the third-year sophomore appears on track to do just that.

While senior John David Booty continued to show good progress coming back from a broken finger, Sanchez took all of the first-unit snaps Wednesday.

“I’m trying to get as crisp as I can, get the timing down with these receivers and have no excuses coming into this game,” Sanchez said.

Coach Pete Carroll again said he would not rush to name a starter.

But Booty has not taken a snap under center since breaking the middle finger on his right hand against Stanford nearly two weeks ago.

“Mark’s preparing to start and that’s why I’m talking to him as the starter,” Carroll said, adding, “What could change is John feels great and he can throw the ball really well. That might be something that we make that choice on as we get close to game time.”

Booty, sporting a receiver’s glove on his throwing hand for the second day in a row, passed accurately during the first half of practice before coaches told him to shut it down to protect from further injury.

“There’s no question that he could play if something happens and we need him,” Carroll said. “If there’s an emergency or whatever he’ll certainly be able to get in there. How much more than that we’ll figure out in the next couple days.”

Booty said he did not require many repetitions to be able to start.

“No matter what they decide, I’m going to be there and if I had to, I could go,” he said.

Sanchez intends to improve upon last week’s effort against Arizona when he overcame two first-half interceptions and led the Trojans to a 20-13 victory. Sanchez completed 19 of 31 passes for 130 yards and a touchdown.

“I need to get better week to week, day by day and it’s got to hurry up because last week, the more times I watch [the film] it’s just unacceptable,” he said. “The effort was there and things like that, but I need to be more efficient.”

Carroll has noticed a difference in Sanchez’s demeanor with one start under his belt.

“The giddiness and stuff has kind of left a little bit, so he’s very cool about it, calm about the preparation,” Carroll said.

Offensive lineman Chilo Rachal (knee) went through team stretching drills for the first time since the Washington game Sept. 29, but he appears doubtful to play on Saturday in anything other than an emergency. Alatini Malu is on track to start at right guard, Carroll said. . . . Offensive tackle Sam Baker (hamstring) will try to practice today. . . . Linebacker Rey Maualuga (hip) dressed for practice but did not participate in drills. “I’m seeing myself playing,” he said. Thomas Williams will start in his place. . . .

Tailback Stafon Johnson (foot) participated in only a few drills and said, “I don’t have a long way to go.” But Carroll said, “I’m hoping he’ll show something [today] to give us some confidence that he’s OK.”. . . Cornerbacks Terrell Thomas and Shareece Wright are nursing hamstring strains, but both are expected to play Saturday.

gary.klein@latimes.com