The Belgian gloveman suffered a fractured nose and eye socket in an aerial challenge against Aston Villa on Saturday and Bruce just hopes he doesn't have to spend too much time on the sidelines.
"Simon had a horrible facial injury, as bad as I've ever seen - and I should know," he told the club's official website.
"We wish Simon well and if anyone can come back stronger, it's him."
And Bruce is sure summer signing Keiren Westwood can do the job in Mignolet's absence after coming off the bench for his Premier League debut on the weekend.
"Keiren has been knocking on the door, I've told him to be patient and now his chance is just around the corner," he added.
"We couldn't wish for a more able deputy. Keiren is an established goalkeeper who's been itching to play in the Barclays Premier League for years.
"Last weekend didn't faze him and I'm sure the next game won't either."