Since donning the protective headgear, Rooney has been able to return to action and score three goals in two games.
"It's not something I really want to wear, but I don't think I'd be able to play if I didn't wear it. It's helped me get onto the pitch so that's the most important thing," said Rooney.
"It's a big learning curve for the manager. His first game in the Champions League proper."
For the big stories and the banter follow us on Twitter: @tribalfootball