Sergio Aguero says bad luck has been a major factor in Manchester City's struggles during Pep Guardiola's first season in charge.
City were beaten 2-1 by Arsenal in Sunday's FA Cup semi-final to end their last realistic chance of silverware under Guardiola this term, having exited the Champions League to Monaco in the last-16 stage and bowing out of the EFL Cup to rivals Manchester United.
The Citizens face United in the Premier League at the Etihad Stadium on Thursday in a match of huge importance in the race to finish in the Premier League's top four.
Argentina striker Aguero conceded it has been a tough season and says City have been punished for their mistakes.
"It has been quite a tough year," Aguero told Sky Sports. "We made a very good start. Our form then dipped, but we managed to recover and had a few good performances followed by a few that weren't quite as good. I don't know if it's been bad.
"We've always played the same way. I think what we've been missing this year is a bit more luck. There have been games that we were winning comfortably and a mistake or lack of concentration cost us a goal.
"In the Champions League, we knew that Monaco would be tough opponents. We produced a good performance at home, but in the away leg I think we gave them the first half.
"You pay dearly in the Champions League if you do that. We reacted in the second half, but it was too late. It's called the Champions League because you're up against the best teams that can make it hard for you.
"We came close in the FA Cup which I think is another example of a game where luck wasn't on our side. In the second half I think both Yaya [Toure] and Fernandinho hit the woodwork.
"If one of them had gone in, it would have been game over. Then we had a goal disallowed when the ball seemingly didn't go out. It's been a tough year, as is always the case in England.
"I don't think luck has been on our side in many games."
Aguero heads into the derby in fine form, having hit 12 goals in his last 12 appearances for City, while he has scored eight goals in 10 games against United, and the Argentine believes Thursday's match at the Etihad is pivotal.
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"As a boy growing up in Argentina, derbies were always incredibly important," Aguero added. "People over there are crazy and as a fan of the club where I started out, Independiente, I wanted us to win the Clasico so badly when I was young.
"I didn't play, but I wanted to beat Racing so much. I was at Independiente and Racing were our rivals. That was my initial taste of derbies and I really wanted to win them, no matter what.
"I was also thinking about something. People are happy for such a long time when you win a derby. It affects the whole city. People can calmly walk around the streets saying, 'we beat you!'
"That's the first thing I thought about derbies. I then went to Atletico Madrid and the derby was against Real Madrid. It was tough. I drew two or three of them, but I lost most. It was a similar story against United when I arrived here.
"Luckily I've now won quite a lot more than I've lost. The game is so important because we need to win to strengthen our position and boost our chances of qualifying for the Champions League."