AFC Wimbledon boss Dave Anderson was left fuming over the lacklustre efforts of his side after their unbeaten 13-match run since the start of the season was ended by Hampton & Richmond.
Lawrence Yaku's 70th minute goal was enough to give the Beavers victory at Kingsmeadow on Saturday when a win could have put the Dons second in the table.
But Anderson pointed to the withdrawal of Scott Curley after just 20 minutes as the major turning point in the game for his side.
"It is the million dollar question whether we would have won had he stayed on the pitch, but all I can say is before he went off we were fine," said Anderson.
"He kicked out at a player off the ball, I saw it and I can't defend it. It is indiscipline and we have talked about it.
"He got booked and then he mistimed a tackle. As soon as I saw that, I knew I had to get him off or he would have been sent off. I certainly didn't want to change things."
Anderson vowed there would be changes ahead of Saturday's FA Cup match at home to Southern League team Evesham United after his side once again flattered to deceive.
Twenty-two-year-old Lewis Cook, who arrived last week from Nationwide Conference South side Lewes, will be given more time to settle in after a promising debut.
But, with the likes of Paul Barnes, Steve Watson and Simon Sweeney returning to fitness, Anderson has promised no player's shirt is safe.
"If we can't get the performances from the players there is a queue of people waiting to take their place ," he said.
"We are not the sort of club where a player has five or six weeks to sort themselves out. They must be ready to play."
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