Tom Brady has said that the New England Patriots' receivers still have a lot of work to do ahead of the start of the 2013 NFL season.
The AFC East champions lost 2012 receiving yards leader Wes Welker during free agency, while tight end Rob Gronkowski is a doubt for the opening game following back surgery.
The team's starting quarterback told reporters: "Everybody's working at it. I would say we have a long way to go and we're doing some good things and we're doing some things that we need to eliminate.
"We were talking last night about how to eliminate mistakes before they happen because we just can't afford to make them and say 'Well, we'll get it the next time.' Those 'next times' are going to cost you wins and losses here shortly.
"The pace picks up there's more installation that goes in. Like I said today, there's more coverages, more things we're seeing, so we've got to be able to incorporate what we're doing in the meeting rooms and bring it out here on the field and execute, really going at a fast speed."
The Patriots face the Philadelphia Eagles in their opening pre-season game on Friday.