Manchester City striker Sergio Aguero believes the 14-point gap between the defending champions and Premier League leaders Liverpool is "too hard" to overturn and says that City need to now concentrate purely on earning a top-four finish.

"Now, Liverpool is too hard. We have to focus just on winning because we need to play Champions League next season. We have to play the same way and see what happens," said the Argentine, City's all-time top scorer.

City beat Sheffield United 2-0 at the Etihad Stadium on Sunday but remain far adrift of Liverpool, who have an extra game in hand. Jurgen Klopp's unbeaten side had earlier beaten Wolverhampton Wanderers 1-0 at Anfield.

Pep Guardiola, City's manager, declined to declare the title race was over but repeated his view that it was pointless to even discuss the issue.

"It's unrealistic to think about it. When a team has the numbers that Liverpool has, why should we think about it, when we are 14 or 17 behind?" he said.

"(We have to) prepare, play good, better, be as close as possible, play the knockout (cup competitions) and prepare for next season. Next season will be here and, hopefully, we can do better."

Asked whether it was now tough after two title-winning years to motivate his team for the more modest goal of qualifying for the Champions League, Guardiola said: "The best motivation is to try to play good, win games, that's the best".

The Spaniard could not resist taking aim at the Premier League fixture list, which saw his team play at Wolves on Friday before being in action 48 hours later.

City are next in action on New Year's Day when they host Carlo Ancelotti's Everton at the Etihad.

"Now, I must say thank you to the Premier League for giving us three days for the next game. We appreciate it," he said.

 Lys Mousset's goal was chalked off

City were grateful to see Lys Mousset ruled marginally offside by VAR after he capped a swift counter-attack half an hour in - another entry on the list of contentious offside decisions over the weekend.

"Press play," said Sheffield United boss Chris Wilder. "I've said it all along. The percentages we are looking at are not big enough. It must be eight or nine goals this weekend. Look at (Norwich's Teemu) Pukki (against Aston Villa), a fantastic finish. The lines are blurred...

"We had a close up of that and the first goal. I just think with these things, there's no conclusive evidence, blurred lines and different angles. There needs to be a more clear way of defining it."

And United were fuming with the officials again after Kavanagh appeared to get in John Fleck's way just as De Bruyne was playing the decisive pass to Aguero for City's opener.

A new rule brought in this summer allows for a drop ball to be awarded if the ball hits the referee at a key moment, but does not legislate for obstruction.

"It was a game-changer, no doubt," Wilder said. "I'm not saying we'd have gone on to win it, but the shape of the team was good. We were not going to come and make it easy.

"It affected the game. (Kavanagh) invited me in after the game and we had a private conversation, he was very open and honest. Whether the PGMOL say anything, that's up to them. I'll keep it between you and me but put two and two together and you'll get the answer.

"I believe if he blows up there wouldn't be a big debate."