The Broncos had been tipped to sweep aside a Jacksonville side in poor form, with some bookmakers offering a record points spread on the match. However, a spirited performance from the visitors made it a much closer contest than anticipated.
Denver were not at their best either, with Peyton Manning throwing just his second interception of the season and the first that was returned for a touchdown, and Welker believes that his team will need to improve in their next match.
"There was a lot of bad football out there. We've got to correct that stuff and come out better next time," Welker told The AP.
The victory means that the Broncos are still undefeated this season, while Manning's two touchdown passes in the first quarter take him to 22 for the season, which is the most any NFL quarterback has ever managed after six games.