After an impressive offensive display by both players, the 18th-ranked Gators take on UAB in Gainesville on Saturday night.
Florida won its first four games last season but finished 8-5 as Brantley struggled to follow in Tim Tebow's footsteps and Rainey ran into trouble off the field.
Rainey was a significant contributor for the Gators in 2008 and '09, combining for 1,227 yards rushing and nine touchdowns. However, he was suspended for five games last year after being arrested for aggravated stalking and was limited to 366 yards and two touchdowns in eight contests.
Rainey looks as though he's put the drama behind him. In a 41-3 win over Florida Atlantic last Saturday, he became the third player in the nation since 1996 to have a rushing touchdown, a receiving touchdown and a return for a touchdown in the same game.
"I thank God all the time that I'm still here," said Rainey, who returned a blocked punt 21 yards. "I stayed here one more year, and that's the best thing that ever happened to me. It's a pro offense, I'm made for it."
Rainey, who touched the ball 18 times in all, is referring to coach Will Muschamp bringing in former NFL offensive coordinator Charlie Weis to lead the offense, which ranked eighth in the SEC last year with 29.8 points per game.
Although they weren't facing elite competition, the Gators finished with 468 yards of offense last weekend, scoring on their first four drives. FAU's lone score came after an interception by backup quarterback Jeff Driskel, who entered late in the first half.
"I think we need to be realistic here," Muschamp said. "We'll face better opponents throughout the season. ... We didn't face as much adversity as we had hoped for, but I'm very pleased with the effort and energy of our players."
Brantley also looks like he'll benefit from playing under Weis' system. Florida ranked 88th in the FBS with 184.3 passing yards per game in 2010, with Brantley throwing nine touchdowns and 10 interceptions.
His performance was more promising last Saturday. Although he had two interceptions, Brantley went 21 of 30 for 229 yards and a touchdown. Last season he passed for more than 200 yards only four times.
"Looked like the old John Brantley you saw in high school," Rainey said. "Being the leader, taking over. He's got all his confidence back."
Florida likely won't face much more adversity against UAB, which opens its season after going 4-8 last year.
Tropical Storm Lee forced the Blazers to move the location of their practices early this week, but they are eager to face the Gators, even knowing they'll be underdogs.
"It's just one of 12 opportunities we have to win," tight end Sam Accursio said. "At the end of the day, you just have to line up and play."
Quarterback Bryan Ellis is back after starting the final nine games of 2010. He finished with 2,940 yards passing, 25 touchdowns and 12 interceptions.
Pat Shed also returns after rushing for a team-high 847 yards and three touchdowns last season. He also had 471 yards receiving and four TDs.
UAB scored 31 or more points five times last season and played close against Tennessee and Mississippi State, losing by a combined eight points.
The teams' only previous meeting was Florida's 51-3 victory in 2002 in Gainesville.