(Reuters) - Here are five storylines to watch during the National Football League's 2014 season, which begins Thursday in Seattle.
The charismatic rookie quarterback was not selected until the 22nd pick of the 2014 Draft by Cleveland but there was no more popular choice than the player known as 'Johnny Football.' A dynamic player on the field and outspoken off it, Manziel set several passing records in his rookie college season in 2012 and went on to become the first freshmen to win the Heisman Trophy as college football's most outstanding player. He will start the season as the backup but Browns fans may demand he take over the offense at the team's first sign of struggle.
The 26-year-old signed a six-year, $126 million contract during the offseason that annointed him as the San Francisco 49ers' quarterback now and into the future. With the massive contract comes lofty expectations for a versatile quarterback entering his second full season as a starter. He got the 49ers to within a win of reaching the Super Bowl last season, one year after taking over the starting role midway through the campaign and leading the team to the title game, where they lost to Baltimore.
After spending much of last season dealing with a bullying scandal that involved since-departed offensive linemen Richie Incognito and Jonathan Martin and made national headlines, the Dolphins enter this season focused solely on football. Despite the distractions, Miami nearly made the playoffs last season as the second wild card but were unable to win one of their final two games. But with the bullying issue in the rearview mirror, Miami could make a successful run to the playoffs.
PEYTON MANNING AND TOM BRADY
The two future Hall of Fame quarterbacks are still competing at a high level late in their careers and neither seems ready to discuss retirement, but the window for each to add another Super Bowl win to their already glittering resumes is closing quickly. Denver's Manning, 38, and New England's Brady, 37, both play for talented teams expected to contend for a title. The oldest signal caller to win the Lombardi Trophy is John Elway, who was 38 years old when he won it with Denver in 1999.
The retooled Texans will be looking to follow in the footsteps of the 2012 Indianapolis Colts and 2013 Kansas City Chiefs when they try to go from worst overall to the playoffs. Houston added new head coach Bill O’Brien and top overall draft pick Jadeveon Clowney to a team that already boasts J.J. Watt, Brian Cushing, Arian Foster and Andre Johnson. Barring injuries, the Texans appear a lock to become the season's most improved team and finish comfortably above last season's 2-14 record.
(Reporting by Frank Pingue in Toronto, Editing by Gene Cherry)