Antonio Conte says it is for the Chelsea board to clarify the reasons why Nemanja Matic was sold to Manchester United.
The 29-year-old Serbian has signed a three-year deal at Old Trafford having been surprisingly allowed to strengthen a direct rival.
Jose Mourinho has expressed his delight at being able to capture the midfielder with whom he lifted the title two seasons ago.
Asked why Matic was allowed to make the move instead of being sold elsewhere, Conte said abruptly: “You have to ask the club about this.”
Chelsea have always maintained that the final decisions on player transfers are down to the manager.
The club are working hard to bring in up to four more players to strengthen the squad following the exits of John Terry, Branislav Ivanovic, Nathaniel Chalobah and Nathan Ake with Diego Costa set to follow.