Dan Evans's Belgian coach, Julien Hoferlin, has claimed British tennis players are "too spoilt".
And the 47-year-old believes Britain's men's number two Evans does not make enough sacrifices to succeed.
Hoferlin, a former Belgian Davis and Fed Cup captain, is returning home after six years coaching for the LTA.
He told Belgian Radio RTBF that the LTA was failing. "The transition between the juniors and the seniors seems to be very, very bad," he said.
"There's not an exceptional 'tennis culture' at club level and the players are too spoilt."
Evans, 24, from Birmingham, made his Wimbledon debut in 2009 and won the fifth and deciding Davis Cup match for Britain against Russia's Evgeny Donskoy in April.
He is ranked 143 in the world and lost in the first round at Wimbledon this week to Russian Andrey Kuznetsov.
Hoferlin said: "He has the potential to make himself a top-60 player, but he makes no sacrifices for his sport.
"He doesn't understand that tennis has to be his priority. For him, it's just a brief interlude in his life."
Hoferlin says he cannot understand why the LTA is failing to produce quality players.
"It is a mystery, but I remain convinced that, with the financial and human resources we have, plus the infrastructure and number of players, we should have been able to produce more."
The LTA appointed Australian coach Bob Brett as its new director of player development earlier this month.
And the 61-year-old will be the "best thing to happen to British tennis in a generation", according to Goran Ivanisevic, who Brett guided to the Wimbledon title in 2001.
"It's going to be success - because Bob won't take any nonsense from anyone," the Croat said. "It's really the best move they have made for a long, long time."