Hastings United Football Club manager Nigel Kane was surprised by the departure of Tom Vickers.
The midfielder left United towards the end of last week to join Ryman Football League Division One South’s bottom club, Horsham.
Kane said: “It’s a mystery to everybody associated with the club. I was very surprised myself.
“We received a seven-day approach for Tom and I didn’t really think he had a decision to make. It’s an awful long journey to Horsham for training and matchdays.
“Maybe he sees that as more of a challenge to help them off the bottom of the league and to avoid relegation. I don’t fully understand the reasons behind his decision.
“I spoke to Tom at training last Wednesday and I know the chairman also spoke to him, but I think he had already made his mind up.
“I wish Tom all the best. Who knows what the future might hold? He may well want to come back to Hastings in the future.
“Prior to his Achilles injury I don’t think there was any argument he was Hastings’ best player last season. He came back quite quickly (from the injury) and probably wasn’t quite 100 percent fit.
“We move on and I’m more concerned about looking forward. We’ve signed an able replacement in Jamie Strong, and Jamie will get better and better and better.”