That is according to former Villa star Dwight Yorke, who weighed in on the ex-Blues youth star.
Maatsen has left Stamford Bridge for Villa Park after an impressive spell on loan at Borussia Dortmund.
"I do think Ian Maatsen is a brilliant signing by Aston Villa," Yorke stated, per football.london.
"Unai Emery has the Champions League next season and we saw him perform brilliantly at Borussia Dortmund, he'll be a good player and builds on Aston Villa's already impressive squad depth.
"I think Chelsea will regret letting Maatsen go, but they have so many players at the club that they clearly don't even know who their best players actually are. Maatsen is another good player they've let go, and it's probably to help out their Financial Fair Play situation."