Buffalo Bills offensive coordinator Nathaniel Hackett has said that the team's rookie quarterbacks have "room for improvement".

First-round draft pick EJ Manuel and Jeff Tuel both made their NFL debuts during the side's 44-20 pre-season win over the Indianapolis Colts at the weekend.

Speaking at a press conference, Hackett said: "I think when you look at EJ, he was very excited. I mean, heck, as a rookie you come in your first game and you're on the minus two yard line. And I thought his demeanor was great out there. He was a little bit fired up I think.

"And then Joe Cool Jeff, heck, he just goes out there and just makes plays. I mean he trusts the reads, he trusts his progressions and it was fun to watch.

"Both of them had some critical errors that we need to clean up and get better at. But both of them are going to continue to get better. For two rookies going into your first game, I thought they did a really nice job. A lot of room for improvement for both of them."

Former Arizona Cardinals quarterback Kevin Kolb is also on the team's roster, but missed the game against the Colts with a knee injury.