The 30-year-old has fallen down the pecking order at Old Trafford due to his long spells on the sidelines with injuries.
Brown told the club’s official website, when asked if he was frustrated at the lack of regular first-team football at Old Trafford: “Yeah, a little bit.
“But I’ve always had to deal with that situation throughout my career. It’s something I’ve learned to handle.
“We’ve got lots of good players in defensive positions. I’m not in there at the moment.
“I have to keep training hard and, when I do get a chance, play well.”
“All you can do is train hard,” he added.
“There’s no point sulking and letting it get to you. It might be difficult, but you have to remember that everyone wants to play every week. Unfortunately, that can’t happen.”