Cincinnati Bengals defensive co-ordinator Paul Guenther has claimed that quarterback Johnny Manziel should aim to emulate Drew Brees.

The 22-year-old struggled in his rookie season as he failed to throw a touchdown, and Guenther thinks that his small size holds him back.

However, he has advised Manziel to follow the lead of New Orleans star Brees, who is also smaller than most quarterbacks but learned to play in the pocket.

He told reporters: "Drew Brees did it. I know Drew is a little bit thicker than Johnny but about the same height. I don't see any reason why he can't do it up there.

"[Manziel] was such a high-profile guy out of college and everyone expected what he did at Texas A&M, but it's a man's game, it's a lot different, and it takes time. You have to take your lumps a little bit."

Manziel was the 22nd pick in the 2014 Draft.