DiMarco (ankle) was placed on the injured reserve list Friday, Maddy Glab of the Bills' official site reports.
The team has been using undrafted free agent Reggie Gilliam at tight end, so it will have to figure something out now that the veteran DiMarco is heading to injured reserve. DiMarco is also a strong special teams player, so the loss is a bit heavier than his modest stats as a fullback would normally indicate.