The 21-year-old has struggled to make a major impact in the Championship.
The forward has endured a difficult first season at Elland Road, having made just eight league appearances for the Whites and failing to score a single goal.
Despite the challenging time he has had in the Championship, the Evening Times reports that Well have been monitoring the 21-year-old's situation for some time now, however the uncertainty over Leeds' former manager Steve Evans' future proved to be a stumbling block to any loan deal being agreed.
However, with United's managerial situation much more certain for the time-being following Garry Monk's appointment, the Evening Times hints that the Scottish Premiership side could now seek some kind of deal for the striker should his first-team chances be as slim under the new boss.
But while Monk may look to make some of his own signings ahead of the new season - which may see Erwin begin the campaign well down the pecking order - the fact that Mirco Antenucci has left the club, and that Souleymane Doukara has failed to find any consistency in front of goal may see the youngster handed more of a chance in pre-season, which may allow Monk to make a decision on whether Erwin has a future with the side, or whether he is free to re-sign for his old club.