Paul Merson says he was shocked by the announcement of Sergio Aguero's departure from Manchester City, but insists Pep Guardiola's side must already have a replacement lined up to let the "goal machine" leave.
Man City confirmed on Monday evening that their all-time record goalscorer will leave the club at the end of the season when his contract expires.
It will bring an end to a glittering career at the Etihad Stadium with the Argentina international helping City win four Premier League titles, an FA Cup and five League Cups over his 10-year stay, and there could be more yet to come with the club still chasing a quadruple this season.
In his latest Sky Sports column, Merson discusses Aguero's legendary Premier League status, the important role he still has to play at City this season, that last-gasp title-winning goal against QPR, what the Argentine's next move could be and who might replace him at Manchester City next season...
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'Aguero is a Premier League legend'
"Legend is a term bandied about too much in football, but in Premier League terms Sergio Aguero is an absolute legend.
"Since the day he first arrived at Manchester City, he's been top drawer.
"I am shocked at the decision, but Manchester City must have someone else in mind.
"They must be bringing in a big name like an Erling Haaland, a Harry Kane or a Kylian Mbappe. Otherwise, how do you not keep hold of Aguero? It's impossible not to keep him. He's a goal machine!"
"I can understand that the injuries he's picked up over the last couple of seasons have played a part, but if you are not bringing in Haaland, Kane or Mbappe, you keep Aguero. Even if he just plays 20 games, he's getting you 15 goals.
"Man City's Achilles heel at the moment is probably scoring goals. For the amount of chances they make, some games they miss chance after chance."
Merson on Aguero's famous strike...
"I don’t think people appreciate how good a goal that was. People get a bit lost in the moment and forget the goal.
"He could have easily gone down that day, taken the easy option and maybe he’d have got a penalty, but he took it on himself and then threw in the dummy.
"How many people would’ve panicked in that situation and just got a shot off straight away? People just don’t understand what an unbelievable goal that was. People say that the goalkeeper probably could have done better but everything Aguero did, his composure, everything, was brilliant.
"You ask top class strikers, players like Ian Wright, and they’ll say it’s all about being ice cool when you get in that position. For him to be able to do that at that moment with what was on the line, that goal will be remembered forever.
'Aguero is City's only natural goalscorer'
"Aguero is the only natural goalscorer at the club.
"They haven't brushed teams aside this season. Even when they were on that incredible run, teams stayed in the game and that was down to City missing chances more than anything.
"And now, when we are getting down to the business end of the season, Manchester City need Sergio Aguero.
"In the Champions League, against the big teams, they will get punished if they keep missing the amount of chances they've missed in the Premier League.
"That's where I can only think that one of the big three, Haaland, Kane or Mbappe, are coming in at Man City next year, and City are thinking that they will be playing every week, Jesus will be the backup and it is disrespectful to Aguero to have him as your third choice striker.
"It would make him a bit-part player, and he's still much more than that."
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'Aguero still has big role to play in quadruple bid'
"What an end to his City career he could have. All four trophies are still firmly on the table.
"They have plenty of scope in the Premier League to have slip-ups, but in the other competitions it's coming down to one-off games, and if you have a bad day, it is gone.
"This is where it becomes really edgy for a team, but if you want to go and win the quadruple, that's what it is all about.
"We've seen it with Manchester United in the past, Dennis Bergkamp missed a penalty in an FA Cup semi-final with virtually the last kick of the game, Jimmy Floyd-Hasselbaink scores in the last minute and Arsenal get beaten at Elland Road and Manchester United go on to win the Champions League with the last two kicks of the game.
"It's fine margins and that's how close you can be to winning the treble, and being remembered forever, or winning nothing at all.
"This is what we are coming down to with City. It's the business end and they will need a bit of luck, and a player like Sergio Aguero."
What next for Aguero?
"There won't be many clubs who wouldn't want a player of Aguero's stature.
"However, clubs will be looking at his injury record and at their wage bills. It will also come down to Aguero too because he'll have to be in a team that creates chances. If you are not getting in and around the opponent's penalty area too often, then it would be difficult to have Aguero in your team.
"He's not getting the ball on the halfway line and beating three players anymore. That's not his game anymore. We've seen some special goals from him where he's scored from nothing, but he's had injuries and is getting on a bit, so I don't see that happening too often anymore.
"It's an important decision for him picking who he plays for next season."
Could he stay in England?
"Will he stay in England or will his next move be abroad? If he stays in England, I think Arsenal would suit the style he would be looking for. They'd be a good choice.
"Mikel Arteta was at Manchester City and the way Arsenal play; they get around the box and they do create a lot of opportunities. Arsenal do tick that box for Aguero.
"But if does he go abroad where the intensity is not as hard as it is in England? He could go somewhere with a different climate and where the games are not as intense as they are in the Premier League.
"That could help with his injury problems as he moves into the latter stages of his career. It's an important move for Aguero as he moves into the final stage of a glittering career."
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And what next for Man City?
"If I was Man City, I'd take any one of Haaland, Kane or Mbappe.
"Whoever gets the chance to replace Aguero at City, they've got the dream job.
"If you are one of those three players, and you get the job at City, you've got to be thinking 30 goals next season, at least.
"People will say about Robert Lewandowski and he's top player, but he's not coming over to England at this stage of his career.
"Any one of Haaland, Kane of Mbappe tick the boxes for City, in my opinion. It's a great move for any of them because they are getting goals."
Haaland, Kane or Mbappe - who fits the bill?
"They are all top players; they all want to score goals and would all fit in well.
"Personally, I think Haaland is the out and out goalscorer, but for me, Kane and Mbappe bring more to the party.
"It will come down to what Pep Guardiola wants. If he wants someone to stay up there and just put the ball in the back of the net, then I think you pick Haaland.
"If you want someone who is going to come in and link up with Kevin De Bruyne, Raheem Sterling, Phil Foden, Riyad Mahrez and Bernardo Silva, then you are looking more at Kane and Mbappe.
"But if you just want a goal scorer like Aguero, a goal machine, then I think you go for Haaland.
"I'd be shocked if Man City do not already know who they want for next season. To say already that Aguero is leaving at the end of the season, it tells me they've already got someone lined up to replace him."