Steven Defour is expected to undergo a scan on Monday after suffering a hamstring injury and could be facing a month on the sidelines.
The Belgian star was forced off just before half time in the 3-1 defeat at Southampton, after pulling up five minutes before the break when clearing the ball out of play.
Sean Dyche will await further news on the midfielder's diagnosis, but it will be a major concern for the manager, with the Clarets facing a tough run of matches in the coming weeks.
Burnley will entertain in-form Everton next weekend, before travelling to Manchester United on October 29 and then hosting Crystal Palace before the next international break.
Defour has been an influential figure since his summer switch from Anderlecht, with one goal and three assists so far this season and Burnley will hope the injury concerns are not as bad as first feared.