Cape Town - Manchester City striker Sergio Aguero believes Liverpool are the only Premier League outfit capable of causing real problems for the defending champions.
City pipped Liverpool to the title by a single point last season but find themselves six behind after 11 games in 2019/20.
The pair look likely to battle it out for the crown once more ahead of a distant chasing pack - although Leicester and Chelsea are both keeping pace with the champions currently.
City were the last team to beat Liverpool in the Premier League, their 2-1 victory in January effectively preventing the Reds from winning the title, earning 100 points and going the entire season unbeaten.
Aguero scored the opener in that game and knows City must avoid defeat at Anfield on Sunday if they have any hope of retaining their title for a third successive year.
"Liverpool has always been a tough opponent. But when I arrived, the team we were fighting for the title was United," Aguero told France Football.
"Initially, it was something strange in the city that City competes against United. Then there was Chelsea.
"But these last four seasons, Liverpool have become a very strong team and are now fighting with us to win the Premier League.
"It's the only team in the league that can hurt us. They have been chasing a new league [title] for years.
"Last season, they didn't go all the way, so they are very motivated. This year, they are in front of us and will try to go to the end."
- TeamTalk Media