MacLean, 27 and currently at Plymouth Argyle, will spend the next week training with the Jambos on a trial basis.
Csabo Laszlo, the Hearts manager, has already decided to offer MacLean and fellow trialist Izale McLeod - from Charlton - contracts until the summer so long as they can prove their fitness.
"I want to bring them here for half a season. I don't like to have a trial and then make a decision. I already have my decision," he told the Edinburgh Evening Nwws.
"We want to see that they are in good condition but they have been training with their teams and I spoke with their clubs. Both players said they would like to come to Hearts."
The Tynecastle outfit have struggled for goals this season, with their top scorer Christian Nade scoring just twice.
MacLean was also a transfer target for Aberdeen. He spent the 2003/04 season on loan at Glanford Park from Rangers, the Glasgow club where he started his career.
He scored 23 times in 42 league appearances for the Iron, and netted twice in cup competitions.