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.

Monday morning's Manchester City transfer talk news roundup:

Graeme Souness tips Manchester United to move for Barcelona's Lionel Messi

Pundit Graeme Souness has claimed that Barcelona forward Lionel Messi could "easily" end up at Manchester United this summer.

Despite his status at Camp Nou, Messi's future remains a constant topic for debate at a time when Barcelona are struggling both on and off the pitch.

With less than a year remaining on his contract at the Catalan giants, the likes of Manchester City and Inter Milan have been linked with approaches for the 33-year-old.

However, Souness feels that United may also take the opportunity to throw their hat into the ring for the Argentina international.

Referring to Barcelona's 8-2 defeat against Bayern Munich on Friday night, Souness told The Times: "Lionel Messi looked like a man who has had enough of carrying that team. Without him they wouldn't even be good enough to qualify for the Champions League.

"This would be the perfect week to put a bid in for the 33-year-old Argentinian and I could easily see him playing in Manchester - at either United or City."

Barcelona are currently in a position where they will have to make player sales before being able to strengthen their first-team squad ahead of next season, while head coach Quique Setien is expected to be removed from his position in the dugout.

Chelsea want John Stones and Lewis Dunk?

Chelsea are reportedly planning a double swoop for centre-back pairing John Stones and Lewis Dunk during the summer transfer window.

Following Nathan Ake's arrival at Manchester City, Stones appears to have fallen further down Pep Guardiola's pecking order, and the England international has been tipped to head for the Etihad exit door this summer.

Meanwhile, a recent report suggested that Chelsea have approached Brighton & Hove Albion over a possible deal for Dunk, who would supposedly cost in the region of £40m.

Now, The Mirror reports that Chelsea will aim to strike deals for both centre-backs as Frank Lampard looks to shore up his defence ahead of next season.

The report claims that the Blues will prioritise the signing of Dunk but could make an attempt to take Stones on loan at Stamford Bridge for the 2020-21 campaign.

Having conceded 54 Premier League goals last season, the Blues are said to be eyeing defensive reinforcements after adding Hakim Ziyech and Timo Werner to their attacking ranks.

Stones will see his current deal at Man City expire in the summer of 2022, while Dunk's contract with Brighton runs to 2023.

More transfer news from Manchester City:

Lionel Messi 'tells Barcelona he wants to leave this summer'
Lionel Messi reportedly tells Barcelona that he wants to leave the club following their humiliating exit from the Champions League at the hands of Bayern Munich. Read more.

Brighton & Hove Albion's Ben White 'wanted by every top six Premier League club'
Brighton & Hove Albion defender Ben White is supposedly wanted by a host of top Premier League sides following his performances for Leeds United in the 2019-20 season. Read more.

Lionel Messi 'considering Barcelona future'
Barcelona attacker Lionel Messi is currently considering his future at Camp Nou, according to a report. Read more.