The Republic of Ireland Under-21 international is set to depart Turner's Cross with the Leesiders deep in negotiations with a number of clubs
Lenihan, 20, has impressed in his performances for Cork City this season, earning international recognition and drawing interest from the likes of Arsenal.
In addition to the Gunners, Caulfield revealed that a host of other Premier League clubs had watched the Republic of Ireland Under-21 international, with a number of English Championship clubs also expressing interest in the defender.
However, the Leesiders have received bids from just two clubs, both of which were rejected, but negotiations remain ongoing with one club.
"Everyone knows who has watched him," Caulfield told reporters at the club's weekly press conference.
"Arsenal have watched him, Hull have. We’ve realised that Manchester United have watched him, Tottenham, Everton and Villa have watched him. They’ve all had direct club employees to look at him
"The official situation is that we received two bids and both have been rejected. One of the clubs has come back to us and we’re in negotiations with them but there's still quite a bit of work to do. There's a lot of talking to be done.
"Do I think that he’ll be gone across channel in the next couple of weeks? I believe that he will, and we have to make sure that we get the proper deal and Brian does too.
"What we have to try and do is a structured deal that if he plays international football or moves on elsewhere, we get rewarded. That’s probably what you have to look at."