Richard Bevan says Andre Villas-Boas was 'frustrated and saddened' to be sacked by Chelsea and has suggested the club are becoming an 'embarrassment'.
Chelsea parted company with Villas-Boas on Sunday after less than a season in charge and owner Roman Abramovich is now looking for yet another new manager.
Roberto Di Matteo has been placed in charge for the remainder of the season, while the likes of Jose Mourinho, Pep Guardiola and Rafa Benitez have been linked with the job on a permanent basis.
However, League Managers' Association chief executive Bevan has questioned the approach of Chelsea following the decision to dispense with Villas-Boas after Saturday's 1-0 defeat at West Brom.
"What's for sure is the club, despite unlimited wealth, haven't yet worked out how to build a successful football club," said Bevan.
"Looking for what is an eighth manager in nine years is a serious embarrassment to the owner, the club, the fans and the league."
Bevan added: "He (Villas-Boas) was very disappointed, frustrated, saddened, but his thoughts were for the club, the fans and indeed Roberto Di Matteo, wishing him well for the rest of the season.
"He's obviously a man who played six years or so for the club and has got good managerial experience with West Brom in the Premier League."
Bevan claimed the frequent managerial changes at Stamford Bridge did not help Villas-Boas develop a relationship with his players.
"Players need to know that the manager's strategy and his job is not in question, there's a clear remit," he said.
"You get success if you get time, and stability will come from that. Otherwise it's very difficult for a manager like Andre to impose his philosophy and build a team."
Villas-Boas' side had won just three times in 12 Premier League games and he had the lowest win percentage of any Chelsea manager since Glenn Hoddle.
Bevan added: "That might be the case. After only eight months you can't build that sort of success. The club's still competing in the latter stages of the Champions League, the FA Cup and fighting for a top-four position. If you want success you must look at the longer term."
Who should be the next Chelsea manager?
Roberto Di Matteo