BATON ROUGE, La. -- Gravel-toned LSU coach Ed Orgeron describes his No. 25 Tigers as "one team, one heartbeat," but there aren't many absolutes as they host Troy in their final non-SEC game of the season Saturday night at Tiger Stadium.

Junior tailback Derrius Guice, expected before the season to battle for the Heisman Trophy after a breakout sophomore season, is doubtful with either a knee or ankle injury for the 3-1 Tigers. He played through the pain and struggled last week in a closer-than-it-should-have-been 35-26 victory over Syracuse.

Senior quarterback Danny Etling threw touchdown passes of 43 and 87 yards against Syracuse within two minutes of game time at the end of the first half and the beginning of the second half, but he was benched for four series in the second half to give some "meaningful" playing time to strong-armed freshman Myles Brennan.

While Orgeron reaffirmed Etling as his starter against Troy, he stressed that Brennan would be inserted for a few series in order to accelerate his learning curve, at least for next season.

Orgeron also hinted he would streamline the offensive playbook, perhaps sending a message to offensive coordinator Matt Canada that his pre-snap motions have been more window dressing than substance.

"You just got to go in there and do the best you can whenever you're called upon to play and try and stay in a rhythm and stay in the right mindset of the game and everything like that," said Etling, who completed 10 of 17 passes for 188 yards and two touchdowns against Syracuse, which nearly erased an 18-point second-half deficit.

"That's probably the biggest challenge of having to deal with (a quarterback change) and to make sure you don't press and do too much now because you feel you need to do that."

Orgeron said even though Brennan is a rookie, he has shown excellent smarts in reading the field, and he likes his stronger arm.

"Obviously, there is a package that we can do with Myles," Orgeron said. "There is an expanded package that we can do with Danny because he knows all the offense. I think that's the difference."

Guice lobbied to Syracuse but carried the ball only eight times for 14 yards before sitting out the second half. Orgeron said Tuesday that Guice was "doubtful" after declaring him definitely out a day earlier. Those predictions have a track record of changing.

"Derrius is out," Orgeron said on Monday. "I don't know if he's going to practice this week, and I don't know if he's going to play. He's a little bit hurt right now."

Also expected to sit out the Troy game is defensive end Rashard Lawrence, who after missing two games with a sprained ankle made his presence felt against Syracuse with five tackles, a sack and another tackle for a loss. But Lawrence injured his other ankle.

"He will not play this week, and hopefully we can have him by next week at Florida," Orgeron said.

Troy (3-1) has won three consecutive games -- over Alabama State, New Mexico State and Akron -- after opening the season with a 24-13 road loss to Boise State.

Coach Neal Brown called the 22-17 victory over Akron, which culminated in a 97-yard, game-winning, drive, a sign that his team could succeed even when not playing at its best. The Trojans forced three turnovers and held Akron to 2.8 yards rushing per carry.

"I think for us to win the game when we didn't play well in any phase shows that we've got a little something about us," Brown said. "Our guys are not going to be intimidated because they've all played in tough venues. Those are opportunities our guys relish."

Brown said the key to making the game against LSU close is to limit the Tigers' explosive plays and containing their running attack, which figures to be led by backup tailback Darrel Williams.

"We can't give up big balls over our heads," Brown said.

Brown also is concerned with the LSU pass rush, especially with outside linebacker/defensive end Arden Key getting his legs under him after returning two games ago from offseason shoulder surgery. Brown said quarterback Brandon Silvers will have to get rid of the ball quickly.

"This is the best pass-rushing team that we'll play all year," Brown said. "They have Arden Key, who may be the No. 1 pick in the NFL Draft. Probably one of Brandon's strengths is that he gets the ball out of his hand."