Burnley boss Sean Dyche has revealed Ashley Barnes has a hamstring injury and he is unsure as to how long the forward will be unavailable.

Barnes sustained the problem during a pre-season clash with Bradford City at the weekend and missed Tuesday’s last-gasp 2-1 friendly victory over neighbours Bolton Wanderers as a result.

Fellow forward Lukas Jutkiewicz also sat out the match at Bolton, although Dyche doesn’t think his injury is too serious. However, the Clarets chief says Barnes could face a longer spell in the treatment room.

“Ashley is unfortunately going to be a bit longer than we hoped.

We are not sure exactly how long yet but he’s tweaked a hamstring muscle,” Dyche told the club’s official website.

“The good news is it’s not in the belly of the hamstring, but we are hoping it will settle down quickly.

“He got off quickly (at Bradford), which is helpful, and Lukas’ is just common sense and a bit of tightness.

“His (injury) is very minor and he trained on grass on Tuesday and will be training the rest of the week.”

It seems unlikely that Barnes will be ready for the Clarets curtain raiser against Swansea at Turf Moor on August 13 but Jutkiewicz could be involved.

Andre Gray is likely to start up front against the Swans, with Wales international Sam Vokes among Dyche’s other options.

The Clarets are 2.50 to kick off the campaign with a victory or 5.50 to win the match with both teams to score.