Butt has made more than 350 appearances for the premier league champions since his debut in 1992-93 but has started only a handful of games this season.
"My situation has looked bleak this season and I would be lying if I said otherwise," Butt told Tuesday's Manchester Evening News.
"At times I have thought maybe this is it for me at Old Trafford. It is dire at the moment.
"It has been frustrating. Any player you ask would say the same thing when they are not playing, particularly when you are playing for your country."
Butt has continued to be involved in the England set-up, winning his 31st cap in last month's 3-2 friendly defeat by Denmark.
But the impressive form of Phil Neville, who has been converted from a full back into a tenacious midfielder, and captain Roy Keane along with the arrival of Brazil's Kleberson have made United's central midfield a very competitive area.
"You want to play in all the games and it is disappointing," said the 28-year-old. "I didn't have showdown meetings with the manager over this but we have had one or two chats about it.
"He has basically told me to be patient and I'll get my chance. He has been true to his word over the years and hopefully that will be the case this time.
"Nobody in their right mind would want to leave this club if they are happy... (but) you do start thinking about having to play away from United when you are in this situation.
"Hopefully, I have a good few years left but the last thing I want is to get to the end of my career and reflect that I wasted so much time when I wasn't playing because you can never get it back."
