Hampton & Richmond Borough boss Alan Dowson has threatened to overhaul his back four if they continue to make the mistakes that cost his side dear at Taunton Town.
The Beavers crashed out of the FA Cup third qualifying round on Saturday thanks to a 2-1 defeat at their Evo-Stick Southern League Division One South & West hosts.
It forced the Beveree chief into an early start on Sunday to assess his options ahead of this weekend's National League South visit of Poole Town.
"It was the worst day of my two years at the club, I'm devastated over the result and I shan't rest until I've sorted it out," he said.
"I can only apologise to the fans and the board, they travelled all that way to see that, and it was nowhere near good enough.
"I was in my office from nine this morning to start sorting the back four out as I barely slept.
"We can't go on conceding like this as it's costing us, if we want to be successful we have to tighten things up.
"I'll be making some phone calls to see who I can get in to improve things in defence."