The Argentinian, who has scored 30 goals this season, has been out for the last three weeks with a knee injury.
City had initially thought the 29-year-old’s problem was not too serious but his continued absence suggests he is also doubtful for the Premier League leaders’ derby clash with Manchester United on Saturday.
Pep Guardiola, speaking at his pre-match press conference at Anfield, said: “He is in Manchester. He did not come. He was injured in the last two to three weeks and is still not fit.
“He is much better but doctors spoke to him today and he said he still has a little bit of a problem and is not comfortable.”
Asked about Aguero’s fitness for the derby – when a victory would see City secure the Premier League title – Guardiola said: “We’ll see.”
Aguero’s absence means Gabriel Jesus is likely to continue up front. The Brazilian, who turned 21 on Tuesday, is still to get back to his best after a spell out with a knee injury in January and February but Guardiola has no concerns.
He said: “Today Gabriel Jesus is 21-years-old and when you are 21-years-old you are not tired.”
City are 16 points clear at the top of the Premier League having played some exhilarating football.
Guardiola insists there is no need to change his approach at Anfield, even though the tie will be settled until after next week’s second leg.
He said: “If I said we are going to do it differently to how we have done, my players would look at me and say, ‘the guy is scared – the manager doesn’t trust us’. That would be a big mistake.
“For us it is a dream to be here in the best eight teams in Europe, and trying to compete to be in the best four.”
City are in their seventh successive season of Champions League football and are aiming to equal their best ever showing of reaching the semi-finals two years ago.
Their history in the competition does not compare to that of Liverpool, who have won it five times, and Guardiola feels a lot comes down to mentality.
He said: “Our best performance is one semi-final in the Champions League. They are five or six Champions Leagues won.
“We accept we are favourites but to do something in this competition you have to feel you are favourites. You have to feel you can do it. If you don’t there is no change.”
Much has been made of the Anfield atmosphere, including the welcome the team coaches are likely to receive, and the influence it could have on the game.
Guardiola said: “We come here to play football. Hopefully everybody, our fans and Liverpool fans, can be correct and polite. It is a game, a sport. We cannot forget that, as good as the rivalry is.
“Liverpool fans will put a lot of pressure on the players but in good terms. That is what it is but it is a nice place to play football.”
Liverpool are the only side to beat runaway leaders City in the Premier League this season in a 4-3 thriller at Anfield in January.
No opposing manager has beaten Guardiola more times than Liverpool boss Jurgen Klopp. In 12 previous meetings, Klopp has six wins to Guardiola’s five.
Klopp was keen to play down the significance of that record, but Guardiola hailed their shared spirit to entertain.
“Both teams try to play. We are the teams that scored the most goals in Premier League this season by far,” added Guardiola.
“I think Jurgen Klopp teams are honest teams that respect what football means. They try to attack and of course we are going to try to (do the same). I’m sure tomorrow is going to be a good game.”
City midfielder Kevin De Bruyne described the sides’ January meeting as a “crazy game” that was “beautiful for the neutral”.
And Klopp called on his Liverpool team to believe they can recreate those heroics despite facing a team the German labelled as the best in Europe at the moment.
“I like the difficult jobs, that is the most interesting thing for a manager,” said Klopp.
“It’s really difficult, but I think we can beat the best. But only if we work really hard and smart.”
While City currently have the upper hand domestically, five-time European champions Liverpool have far more pedigree in continental competition.
However, the Reds haven’t reached the Champions League last four for a decade and Klopp wants modern-day memories created at Anfield.
“This club is already so full of history and we have to write our own history,” said Klopp when quizzed whether he was seeking inspiration from Liverpool’s glory days in Europe.
“People meet me in the street and they can tell me each goal and who scored 37 years ago in the 56th minute… we need to be proud of our history but we need to create our own history.”
Liverpool centre-back Joel Matip will miss the rest of the season with a thigh injury, while Adam Lallana will miss both legs against City due to a hamstring injury suffered in Saturday’s 2-1 win at Crystal Palace. German midfielder Emre Can missed that match and remains a doubt with a back injury.
Real Madrid and Juventus know each other well.
Aside from meeting in Europe for the 20th time – the second-most-contested fixture in the competition – the two sides of course met in last year’s Champions League final, with Los Blancos decimating the Serie A giants 4-1 in Cardiff.
Not much has changed in the way of personnel since. But Juve arrive for the last-eight tie with added steel after last May’s crushing defeat.
Massimiliano Allegri’s side have dragged themselves back to the top of Serie A in recent weeks, putting an unprecedented seventh straight Scudetto within their grasp. They also displayed tremendous guile and grit to eliminate Tottenham in the last-16.
Conversely, Madrid have struggled domestically with their La Liga title all-but surrendered to bitter rivals Barcelona.
In Europe, the narrative has been reversed. With practically a fully-fit squad to pick from, the two-time consecutive winners – and 12-time champions overall – will be hopeful of coming away from Tuesday’s clash in Turin with a positive result, especially with the hosts missing key men Miralem Pjanic and Medhi Benatia through suspension.
With that in mind, we examine the key battle for the clash.
Gonzalo Higuain v Cristiano Ronaldo
Football and the business sector have many things in common, but the main one is a love for an acronym.
Juventus possess their ‘HD’ Argentine partnership of Gonzalo Higuain and Paulo Dybala, while Madrid counter with their trio of Gareth Bale, Karim Benzema and Ronaldo to former the ‘BBC’.
HD are both struggling for their national side – Dybala was dropped from last month’s Argentina squad and Higuain is finding it troublesome to get the ball into the net.
Higuain spurned the type of simple chances he’s clinically dispatched at club level this season and he’s actually enjoying one of his most prosperous Champions League campaigns, with five goals to his name already.
A classic No9, Higuain is durable, relentless, hardworking and efficient in front of his goal with his intelligent diagonal runs sure to cause a positionally lax Madrid backline issues.
Ronaldo, true to his personality, has been Jekyll and Hyde on the pitch this season. The first half of his campaign mirrored Madrid’s – torrid.
But since the turn of the year, the Portuguese star has been in tremendous form.
Before January he had only managed four league goals, but in 2018 the 33-year-old has scorched, netting 18 times. He’s remained consistent throughout the Champions League despite his domestic difficulty, plundering 12 times – four more than Sevilla’s second-placed Wissam Ben Yeder – with a goal arriving every hour.
The bigger the stage, the better he is. A fundamental difference in Ronaldo’s style since January is that he’s looking to finish attacks rather than drop deeper to influence in the build-up.
Juve are facing the game’s greatest poacher.
Los Blancos emerged 4-1 victors on that day, but a much-closer contest is expected this time in 2017/18’s quarter-final opener.
With the second leg coming next week, the pressure is on for a fast start.
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