New York Giants co-owner John Mara has insisted that quarterback Eli Manning is not in decline and believes that he will perform at a high calibre in the 2014 season.

The 33-year-old struggled for the Giants last season throwing more interceptions than touchdowns, just two seasons removed from his second Super Bowl win.

"I don't think he all of a sudden forgot how to play quarterback," Mara told the New York Daily News. "We expect to see the championship-level Eli play for us this year."

Manning had surgery on his ankle during the off-season, which is reportedly set to limit him during his side's organised team activities in May.