Caldwell told Express Sports: “Since Paul’s loan spell came to an end, I’ve been in regular contact with his agent and I spoke to him just 48 hours ago.
“Paul thoroughly enjoyed being a part of everything we have here at St Mirren and he relished the opportunity to play first team football.
“Right at this moment in time, that’s the big thing for him. He is at an age where he has to be playing and, having had a taste of life in the SPL, he wants more.”
He added: “The current situation is that Newcastle were looking at including him in their squad for this weekend’s game but they expect to have players back from injury next week and are also looking at signing new defenders.
“Should that be the case and we can come to some arrangement with Paul’s agent, then he could be in our squad for the match against Ross County next weekend.
“Failing that, it could be the following weekend, when we play Celtic in the League Cup semi-final, that we could have him back. Danny wants him back and, having spoken to Paul, I know that the lad is desperate to return.”
Caldwell is delighted the Saints have such a good working relationship with Premiership giants Newcastle, aided by the presence of assistant manager Tommy Craig.
He said: “Tommy was at Newcastle for years and is still friends with their reserve coach Willie Donachie, as well as others on Tyneside.
“Apparently, Newcastle are happy Paul returned to St James’s Park a far better player than the one who left, so they can see that the loan arrangement with St Mirren is a win-win situation.