Kevin Kyle may miss the start of the season after being told his knee requires more surgery.
The summer signing from Kilmarnock was absent from the club's pre-season training camp in Italy after suffering discomfort during his first week of sessions following the initial operation.
Hearts manager Jim Jefferies told the club's official website: "The mesh which keeps it (the knee) reinforced came away a wee bit so he needs a small operation to tighten that up. They thought they would get away with an injection so we're back to what we should have maybe done at the start. It's probably a two or three-week thing, so he might miss the start of the season."
Jefferies added: "He'll be a miss for the start of the season but you never know. Even if I could get him handy for the bench if I needed him to come on, if he could not manage 90 minutes."
However, there was some good news for Jefferies as Lee Wallace has recovered from a calf injury.
The left-back has been named in the squad to travel to England for friendlies against Gillingham and Millwall.
Polish midfielder Adrian Mrowiec will also feature as Jefferies weighs up a contract offer, but Finland international Kari Arkivuo has returned home after his trial spell.
Jefferies is still missing Ruben Palazuelos, Gary Glen, Jason Thomson and Andrew Driver through injury.
Source: PA
