Sergio Aguero has labelled Manchester City's decision to sell Raheem Sterling 'strange' following the England international's move to Stamford Bridge earlier this summer.
The 27-year-old joined Chelsea in a deal worth £50 million having spent six years at the Etihad Stadium.
And former City man Aguero, who was forced to retire last year with health issues after a brief stint at Barcelona, has questioned the logic behind Sterling's exit.
What has Aguero said about Sterling transfer?
"I don't understand the sale of Sterling," Aguero said on his Twitch channel. "There are times they (City) make strange decisions."
Despite Aguero's concern, Guardiola has insisted the time was right for Sterling to move on.
He said: "There are decisions for the club and decisions for the players. I said from day one since arriving here you have to be where you want to be.
"Raheem made this explosion of something incredible and unpredictable. I saw his ambition to score more goals and assists grow. I would say the impact for the way he played and never got injured was top."
What has Aguero said about Haaland arrival?
The £100 million signing of Jack Grealish last summer has left City boss Pep Guardiola with a dearth of options in wide areas.
Sterling was clearly deemed surplus to requirements, although Aguero suggested his departure could make life more difficult for the club's newest big-money arrival, Erling Haaland.
Commenting on the striker's debut for City in last weekend's Community Shield defeat to Liverpool, Aguero added: "He was too used to Germany, Haaland thought he was alone, then Van Dijk arrived and said 'welcome to the Premier League'."