The arrest and subsequent suspension of LSU football players Jordan Jefferson and Josh Johns on Friday gave the Tigers some clarity one week before their season opener.

They know that senior Jarrett Lee has replaced Jefferson as the starting quarterback and that Jefferson and Johns, a third-string linebacker, will be unavailable for the indefinite future.

They also know that freshman wide receiver Jarvis Landry and sophomore offensive tackle Chris Davenport, who were interviewed by police along with Jefferson and Johns in a bar fight but weren’t charged, remain on the team.

And now it’s full speed ahead to the eagerly anticipated opener against No. 3 Oregon on Sept. 3 in Arlington, Texas.

“I think we all understand our marching orders,” head coach Les Miles said after practice Friday. “I think our team understands that there’s not much that they can do specifically to help either Josh or Jordan. It’s more about preparing to play.”

Lee, who has a 5-4 record as a starter at LSU, including a 4-4 record as a redshirt freshman in 2008, will take the majority of practice snaps with the first-team offense. His last start came Nov. 14, 2009, in a 24-16 win over Louisiana Tech in Tiger Stadium.

The next three quarterbacks on the depth chart — sophomore transfer Zach Mettenberger and true freshmen Stephen Rivers and Jerrard Randle — haven’t played in a college game.

Miles said Lee had “a hell of a practice” Friday and that the Tigers had been preparing for the possibility that Lee might replace Jefferson since the investigation into the bar fight at Shady’s began a week ago.

Lee said earlier this week that he always prepares as though he’s going to start.

“All of us quarterbacks know that in order to be good you have to prepare each and every day to be the starter whether your opportunity comes or not,” said Lee, who sat out LSU’s championship season of 2007 as a redshirt. “I’ve been in this system now for five years. I know you can be only one play away, so my preparation hasn’t changed at all.”

Lee said first-year quarterbacks coach Steve Kragthorpe, who worked extensively with Jefferson on his mechanics, has also helped him.

“Coach Kragthorpe coming in was a huge asset to me,” Lee said. “When it comes to being in the film room and watching film, it’s not something I’m going to say I was bad at, but it’s something he made me really progress at.

“Coming into this season now and watching film on Oregon and seeing what they do and what works best against them has helped me tremendously. That’s something he has really helped me with.”

Lee, who’s from Brenham, Texas, played in 11 games in relief of Jefferson last season. He completed 54-of-89 passes (61 percent) for 573 yards with two touchdowns and one interception.

Lee has led LSU from behind in the fourth quarter to win games four times in his career, including a 33-29 victory against No. 12 Florida in Gainesville last season. He completed 9-of-11 passes for 124 yards and two touchdowns, including a game-winning 3-yard scoring pass to Terrence Tolliver with six seconds left.

He played in seven games in 2009, including the start against Louisiana Tech, when Jefferson was sidelined by an ankle injury. Lee completed 7-of-22 passes for 105 yards and a touchdown.

Lee started eight games in 2008 before an ankle injury sidelined him for the last two games. He finished the season with the second-most attempts (269), completions (143), passing yards (1,873) and touchdowns (14) by a Tigers freshman, though he also threw 16 interceptions.

LSU had two come-from-behind wins with Lee at quarterback that season, including the largest comeback in school history. The Tigers trailed Troy, 31-3, early in the third quarter before scoring the final 37 points to prevail, 40-31, in Tiger Stadium. Lee completed 20-of-34 passes for 216 yards and a touchdown.

“Jarrett does a lot of things well,” center P.J. Lonergan said. “He’s a good guy, a good leader. Jarrett is a key part of this team. I’m glad we have him.”

LSU figures to use fewer running plays for the quarterback with Lee than they would have with the more athletic Jefferson, though Lee, 6 feet 2 inches tall, at 206 pounds is about 20 pounds lighter than he was last season.

“I feel a little more athletic and a little more mobile,” Lee said. “(Running) is not something I’ve been known to do, but it’s something that I can do. If something happens, I’m going to make it happen with my feet. I’ve tried to work on that.”

In addition to losing weight, Lee said a priority of his coming into this season has been “being poised and staying calm. I think that’s one thing that I’ve definitely matured at,” he added. “Coming off of last year and coming into this fall camp that’s something I felt like I really needed to work on.”

Lee, like Jefferson, has often been ridiculed by fans on talk radio and in chat rooms because of his erratic play. Earlier in the preseason, Jefferson was asked about Lee’s perseverance.

“He has broad shoulders,” Jefferson said. “Being criticized is very difficult. He stays humble, comes to practice every day, gives 110 percent, He’s a great guy and a good quarterback. I’m happy he’s here with me.”