Guernsey boss Tony Vance admits their FA Cup replay against Thamesmead Town on Tuesday will be a costly burden.
The Green Lions, hosting the first ever cup match on the island, forced the preliminary qualifying round tie to a replay with a 2-2 draw on Saturday.
Guernsey, who often struggle for player availability, now travel to London.
"Okay we got something out of the game, but more so it is a game we could have done without from a financial and logistical point of view," Vance said.
Guernsey, who play in English football's eighth tier, battled back from two goals down in front of a crowd of 1,142.
Dave Rihoy scored both goals for the hosts after the break, helping makeup for what Vance said was an "awful and lifeless" first-half performance.
"It wasn't good enough, we didn't have the right energy or movement. We were reactive and not proactive and put ourselves in a situation where we had to try do something.
"As much as I'm frustrated with the players for first half, I'll give them loads of credit for the second half. I'm proud."
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