The summer transfer window has now begun, with rumours and speculation continuing to swirl as Manchester City eye possible reinforcements.

The 2018-19 champions did not bring in a single player during the January transfer window, despite suffering a defensive shortage for much of the 2019-20 campaign, but they have already started their business for the summer.

Here, Sports Mole rounds up the latest news on possible comings and goings at the Etihad.

Thursday morning's Manchester City transfer talk news roundup:

Napoli offer Manchester City £60m Kalidou Koulibaly deal?

Manchester City have reportedly been offered the chance to sign Napoli defender Kalidou Koulibaly for £60m this summer.

The 29-year-old has been frequently linked with a move away from Serie A after establishing himself as one of the world's leading centre-backs during his time in Naples.

City have supposedly struggled to agree a fee with Napoli for the Senegal international in recent weeks, but Napoli are believed to be determined to get a deal done as they pursue defensive options of their own.

According to The Mirror, Napoli are prepared to lower their asking price for Koulibaly from £72m down to £60m, and the player himself would favour a move to City over bitter rivals Manchester United.

Napoli have supposedly identified Lille's Gabriel Magalhaes as Koulibaly's replacement, but the Serie A side must sell before they can buy amid reports that Arsenal have agreed a deal for the Brazilian defender.

Pep Guardiola has already bolstered his City defence with the acquisition of Nathan Ake from Bournemouth, and the Citizens are also said to be keen on Sevilla's Diego Carlos.

Gonzalo Higuain warns Barcelona's Lionel Messi over Premier League move

Gonzalo Higuain has warned compatriot Lionel Messi that it would take time to adapt to the physicality of the Premier League.

Despite his status at Barcelona, speculation persists that the 33-year-old may opt to depart Camp Nou during the summer transfer window.

While the Argentine has been linked with Inter Milan, there is also talk of a potential switch to Manchester City or Manchester United.

However, after he failed to make a sustained impact during a loan spell with Chelsea, Higuain has suggested that his compatriot would be in for a culture shock.

Speaking to Fox Sports, Higuain said: "I suffered a lot in the Premier League and couldn't adapt in those six months.

"It's nothing like La Liga. There, the defenders rough you up with kicks and they don't blow for free kicks like they would in Spain.

"I don't know how that would affect Messi. I don't think he would suffer, since he is a player at another level."

Messi currently has less than a year remaining on his contract at Barcelona.

More transfer news from Manchester City:

Chelsea, Manchester United, Manchester City 'battling for David Alaba'
Chelsea, Manchester United and Manchester City are all interested in signing Bayern Munich defender David Alaba this summer, according to a report. Read more.

Willian 'had no intention of leaving Chelsea'
Willian allegedly had no plans to leave Chelsea this summer until it became clear that club officials were happy to hand him a free transfer. Read more.

Manchester City ahead of Manchester United in Jack Grealish race?
Manchester City are reportedly showing more interest in signing Aston Villa playmaker Jack Grealish than long-term admirers Manchester United. Read more.

Lazio chief Igli Tare has 'no respect' for David Silva
The former Manchester City midfielder had been on the verge of a free transfer to the Serie A club before opting to join Real Sociedad on Monday. Read more.

Manchester City extend Scott Carson's loan deal
The 34-year old will remain at the Etihad Stadium as back-up to Ederson. Read more.