Aston Villa manager Paul Lambert has accused Southampton manager Ronald Koeman of lacking respect in his apparent pursuit of Ron Vlaar.
Koeman was quoted in the Dutch press last week as saying he would "really like" to have the Netherlands defender at Southampton.
"He is disrespecting when talking about other team's players," said Lambert.
Vlaar, 29, was one of Lambert's first signings at Villa, arriving for a reported £3m fee in the summer of 2012.
The centre-back had previously been at Feyenoord, where he worked under Koeman.
"I wouldn't mind if he picked up the phone, but you don't go public on it," Lambert added on Sky Sports. "That's the thing that annoyed me the most.
"I just thought it was the wrong thing to have done."
Koeman has made no secret of his admiration for the Villa captain, although appeared to temper his interest last week when he indicated the arrival of Florin Gardos had ended his search for a central defender.
"He is a great central defender. He was one of the names on our list, but now we have Florin Gardos," Koeman said when asked about Vlaar.
Vlaar, who impressed in the Netherlands' run to the World Cup semi-finals, has a year left on his deal at Villa Park, although the club are planning to offer him new terms.
Villa kicked off the season with a 1-0 win at Stoke and Lambert believes Vlaar's performance in that match proved he was not distracted by speculation over his future.
"You saw Ron play on Saturday. He was fantastic for us," he said. "I don't think anything like that is preying on his mind at all."