Hull City have suspended midfielder Jimmy Bullard "pending an inquiry into recent events".
The 32-year-old joined the Tigers for a club record £5m in 2009 when they were in the Premier League.
A statement on Hull's website read: "We will be completing the investigation before making any further comment."
BBC Radio Humberside understands that the suspension is over an alleged breach of club discipline on the club's recent tour of Slovenia.
Bullard ended last season on loan at Ipswich Town and the Tigers have been trying to sell him because he is on a reported £50,000 a week.
The former Peterborough, Wigan and Fulham player has made just 24 appearances for Hull in two and a half years.