Bernardo Silva believes former team-mate Kylian Mbappe is undecided over his Monaco future.
Silva left the Ligue 1 champions for Manchester City in a deal reported to be worth an initial £43 million last week.
It could prove to be a busy close season for Monaco as they aim to ward off potential suitors for other members of Leonardo Jardim's squad, where teenage sensation Mbappe is the star attraction.
The 18-year-old enjoyed a stunning breakthrough season, earning his maiden caps for France and scoring 26 goals in all competitions as Monaco also reached the semi-finals of the Champions League.
Silva was often the man providing the ammunition for his livewire team-mate and told RMC Sport Mbappe has enviable options, amid speculation Real Madrid will launch a world-record bid.
"Honestly, I think even he does not know if he's going to stay or go," Silva said.
"He's a fantastic player who had an incredible second half of the season. I think he is [happy] in Monaco, but if he goes to a big club to play, it's also very good for him.
"He's very young, and it would be nice to stay a year longer, but his age is incredible, so you never know."
City have been linked to another raid on Monaco for left-back Benjamin Mendy – a move Silva would welcome.
"Benjamin Mendy is a friend and if he can play with me it's better than against me," he said.
"Especially as a left defender and me on the right or in the middle."
Those two positions, the right-sided attacking role from which he roved brilliantly for Monaco or a more central playmaking brief, are where City boss Pep Guardiola expects to use his first marquee signing of the close season.
"We spoke about it for about 10 minutes after my signing," Silva said of Guardiola. "He told me that I had to adapt to the championship, to the club, and he told me what position he wanted me to play in.
"He sees me on the right or in the middle. I can play both positions, but I can also be on the left if necessary. "
He added: "When I had the opportunity to play in the Premier League, to be coached by Guardiola and to evolve with players like [Kevin] De Bruyne, [Sergio] Aguero or [David] Silva, I could not refuse.
"It is also a good offer for Monaco. I am very happy [to be joining] the best championship in the world."