Wayne Rooney says he is hurting from seeing bitter rivals Liverpool fight it out for the Premier League while Manchester United are an afterthought in the title race.
Brendan Rodgers' second-placed side are currently seven points off leaders Chelsea with a game in hand and travel to Old Trafford to face United on Sunday.
But Rooney's side are a distant 18 points off the top and are facing the huge disappointment of failing to qualify for the Champions League for the first time in 19 years.
Manchester City occupy fourth spot, the lowest rung United would have been prepared to accept at the start of the season, and are nine points ahead of their neighbours with two games in hand.
Rooney admits watching City lift the League Cup and contend for the title, coupled with Liverpool's emergence as contenders makes for painful viewing.
"To see City doing well, and particularly Liverpool, is really difficult," Rooney told official club magazine Inside United. "It's not nice when we know we are capable of being up there challenging and we haven't been doing that this season.
"However, it means we have to step up and get back up there because the feeling we've had this season is not a nice feeling at all to have. We have to keep working, keep progressing and finish the season stronger."
United cantered to their 20th league title by a margin of 11 points last season, but have struggled in David Moyes' first campaign since replacing the retired Sir Alex Ferguson.
Moyes has taken plenty of flak for United's poor season, which also sees them facing an uphill task to progress to the Champions League quarterfinals after a disappointing 2-0 defeat to Olympiakos in their last-16 first leg.
However Rooney has placed the blame squarely on the players' shoulders, saying: "As a group of players and a team we haven't been good enough this season and we have to put that right.
"After Sir Alex being here for 26 years, there was always going to be a change whoever came in and, in fairness, I think the players have to do better. Hopefully we can make the top four but, if not, we will still come back firing for next season."