Harris filled in for a struggling Anthony Jennings Saturday night and finished the Tigers' 63-7 win over New Mexico State with 178 yards and three touchdowns passing on 11-of-14 attempts to go with 36 yards and two touchdowns on five carries.
"Harris came in and gave us a great spark," said Miles. "The team played well around him. He did a very nice job, made good decisions.
"It stands to reason he'll get the first snaps against Auburn."
For the season Harris has totaled 394 yards and six touchdowns versus one interception (on a Hail Mary) through the air, completing 73.3 percent of his attempts, while rushing for 108 yards and three touchdowns as a backup.
Jennings, who has started every game for LSU since Zach Mettenberger went down with an injury in last year's Arkansas game, has passed for 734 yards, five touchdowns and three interceptions this season, completing 50.6 percent of his passes. The sophomore was intercepted twice on five pass attempts in the first half of Saturday night's home game.
The start on the Plains will be the first of Harris' career. Miles said while it's impossible to completely prepare Harris for the rigors of a hostile road crowd, the LSU staff will do certain things to make the Bossier City native comfortable.
"You can't prevent it," continued Miles. "The scheduling of plays and making sure you format a script and everybody understands what's expected, that's what he did Saturday. He took the plays we asked him to. If he handles it that way, we'll be fine."
Miles isn't typically so forthcoming to the media when it comes to personnel decisions, particularly at the quarterback position. But Miles wanted to make sure his young quarterback, and everybody else for that matter, knew exactly where he stands.
"He needs to know," Miles said. "It's not going to be something I hide from him. I don't want him to have to field the questions ... I think he deserved the opportunity to take snaps. It wasn't a difficult decision."
As for Jennings, Miles didn't dismiss the notion that he'll take the field at Auburn in Saturday's key SEC West showdown.
"We'll always view the game and see how that's going. Sometimes there's an opportunity for another player to give a player that has the burden on his plate a series or situation off," Miles explained. "I'm not saying we'll do that, but we're very capable to see how the week goes, and we have a lot of confidence in both guys, certainly in Harris and we'll see how it goes."