The news of Florida quarterback Will Grier testing positive for a performance-enhancing substance sent shock waves through the college football world, and now it's really going to test the mettle of the Gators and their coaching staff.

Barring a successful appeal, Grier, who had turned in the best performance by a Florida quarterback through six games since Tim Tebow, will miss the remainder of the 2015 season and the first six games of the 2016 season, too. The first quarterback since Tebow in 2009 to throw for 200 yards in three straight games and the SEC's leader in completion percentage (65.8) and scramble yards (154) carelessly made a grave mistake by not checking with Florida's medical staff before putting a supplement into his body.

But the Gators can't worry about that. What's done is done, and now the 6-0, overachieving Gators must try to keep this improbable 2015 run going without one of its most important players.

Here's the reality for the eighth-ranked Gators: They must play football this weekend and at least six more times after that. The Gators had their time to sulk and steam over Grier's suspension when he met with the team and apologized Monday afternoon. Now, it's on to No. 6 LSU and trying to stop Leonard Fournette inside Tiger Stadium, where the Tigers are 33-9 against SEC opponents under Les Miles. After that, it's time to game plan for Georgia with a chance to essentially clinch the SEC Eastern Division.

Florida is still undefeated with a lot to play for and has time on its side.

No one is going to feel sorry for the Gators, so neither should they. Sophomore Treon Harris, who started the season opener and Florida's final six games last year, is now the starter for the foreseeable future. If this team wants a chance at winning the SEC Eastern Division, it'll have to rally around the not-so-new guy who already has tremendous respect from his teammates.

Harris is limited as a passer, but he has looked decent in limited work this year. With a more pass-first approach during the first two games of the season -- when Harris and Grier were sharing time -- Harris was 19-of-27 passing (.704) for 269 yards with two touchdowns and no interceptions. He hasn't thrown a pass since Week 2, but coach Jim McElwain said on Monday that he trusts Harris can make the same throws Grier did.

"Obviously we were putting things in for him as we kind of go," McElwain said of Harris. "He's been doing a great job in practice. As you know going into this, I felt that we've had two really good quarterbacks. Now it's Treon's opportunity to take the reins and run with it. He'll do a great job."

It's important to remember Harris has cut his teeth in the SEC before and was even the quarterback for the Gators when they upset Georgia by 18 last year. Harris removed himself from the quarterback competition earlier this year when he was suspended, and then Grier played well enough to keep his job. The offense will be altered somewhat to fit Harris' strengths, but we won't know how much until Saturday.

That's all on the coaches. McElwain and offensive coordinator Doug Nussmeier have already done a stellar job turning this offense -- especially the quarterback position -- into an actual threat, but now it's crunch time for these two. They had weeks to work with Grier, who was taking the majority of the snaps. They have just a week to outthink a tremendous LSU defense that ranks in the top four of the SEC in total defense, passing and rushing defense.

McElwain's quarterback whispering will really be put to the test against LSU. It's all about adjusting to make Harris both comfortable and a threat, meaning McElwain and Nussmeier could have longer days at the office this week.

This is also about a team that started the year with zero expectations responding now that it actually does. The Gators went from afterthought to East favorite with Georgia, Tennessee and Missouri all sitting with two conference losses. Florida has a spark on offense -- thanks in large part to Grier's recent play -- but it also has a new mindset that McElwain has instilled. We'll find out how mentally tough this team is.

Pieces around Grier have stepped up. Receivers Antonio Callaway and Brandon Powell are having breakout starts, while Demarcus Robinson continues to impress with highlight-reel plays almost every week. The offensive line seemingly grew up overnight, and McElwain has made the tight end position key again at Florida in fewer than 12 months on the job. Oh, and that defense is still dominant.

Now, all those pieces must adjust to and trust Harris. We've seen Harris provide a spark for the Gators before, and now he has a more offensive-minded coach helping him. Moving forward without Grier is manageable -- it's just going to take some work.