Dundee manager Smith says Harkins would lift the SPL strugglers both on and off the park - should a deal be done.
Smith revealed earlier this month that agreement had been reached with Kilmarnock to take the midfielder back to Dens Park on loan.
Harkins had a successful spell with the Tayside club between 2009 and 2011, before sealing a move to Rugby Park.
Reports claim the deal has stalled because the player's advisors want the loan to be a permanent move instead.
Smith said: "It's a case of if it happens, it happens. Everybody knows that he was a fans' favourite here and the qualities he's got are qualities we need.
"I'm sure everybody in the dressing room would be boosted, not just on the park but off the park, where he's a good character to have around the dressing room.
"He enjoyed his spell here. I know he's got great affection for the club and I'm sure if there's any club he would like to come back to, it's us."
The SPL's bottom side head into the second half of the season hoping to halt the losing streak that saw them fail to pick up a point from their last four games before the winter break.
Smith added: "Everybody just wants to get back playing and to give themselves every chance of staying in this division.
"It can work two ways in that the break may have given them time to think about it, but it's also given them the motivation and time to think positively about how we can get out of this situation.
"I'm sure those positive thoughts will get us out of it."
Dundee travel to Easter Road on Saturday to face a Hibernian side who provided their last victory in the SPL in November.
Smith said: "We've had two contrasting games against Hibs. In one of them, they did extremely well at Easter Road. But we will focus on the performance against them here where we did extremely well.
"The players did everything we asked of them and we got a good result. We will be asking them to do similar things.
"They can take confidence from the fact that they've beaten them at Dens and they must take all the good things that we did in that game into the game on Saturday."