The Austrian is back at the DW for his second spell.
"It was great to see him back - and we all have fond memories of Scharns both as a player and as a person," Boyce told the Wigan Observer.
"He's a good footballer, great in the air, he reads the game well and is quite quick. And as long as his head's right he'll be a massive asset for us.
"I think the manager has done fantastic to get him back here - he'll have a point to prove, to show he can still do it in the Premier League.
"It's a great move for all parties."