Worcestershire's agreement to bring back Saeed Ajmal this season could fall through if Pakistan's proposed tour of Sri Lanka goes ahead.
Pakistan star Ajmal has re-signed for the Royals to play in the Friends Life t20 this year after enjoying an initial successful spell at New Road last season.
But there is a possibility of Ajmal, who recently took 24 wickets in three Tests against England, being needed for international duty in June.
"We are aware of the possibility of Pakistan touring Sri Lanka and the impact that could have as regards Saeed," Worcestershire chief executive David Leatherdale said.
"We were aware when we signed Saeed that there was the possibility of Pakistan touring but there has been no definitive answer. We don't know if they will be touring or not.
"Saeed has signed for us, he is desperate to come, he is a class act, and if he can't come back it will be a blow.
"If he is available then fantastic, if not then it will be a real shame but we will look at some other plans."
Ajmal helped his country to a 3-0 Test whitewash win over England and also took a five-wicket haul in the opening one-day international on Monday.