Ex-Everton No2 Irvine said: "There was a bit of speculation linking us with David in January and Harry responded by saying that Portsmouth would hardly allow him to come back to us so soon after spending £6m to get him!
"David is Harry's player, so I am not in the business of trying to stir anything up between the two clubs.
"But if Harry was to ask me whether I fancied taking David back on loan, then that would be a different matter.
"There was certainly a lot of interest among several Premiership clubs in David last summer and, as assistant to David Moyes at Everton, I know they were one of them.
"David's a top quality goalscorer, but the step up from the Championship to Premier League can be a big one."