Maidstone defender Jack Parkinson appeared on trial for League 2 Leyton Orient on Tuesday night.
Parkinson, who is looking to secure a move to full-time football, played 90 minutes as Orient won 4-0 at his former club Woking. He's set to play for the Londoners again on Thursday.
Stones boss Jay Saunders said: "Orient saw him playing for Cambridge the other week and wanted to have a look at him.
"They won 4-0 and by all accounts he did well. I believe they're going to have another look at him on Thursday."
Parkinson was given permission to pursue full-time football after leaving his job with United's academy.
Saunders would like the situation resolved before the National League South opener at Sutton on August 8.
He said: "It depends on who comes in. It's got to be a club that's willing to take him and one Jack's willing to go to.
"It's an awkward one. It becomes very hard for him to start the season with us.
"I've no replacement in mind should he leave but I'm always on the look-out - you have to be.
"It's a difficult situation because if Jack's off the budget, there's money to spend. If he's not, there isn't."