The transfer window is now open again, with rumours and speculation continuing to swirl as Manchester City eye possible January reinforcements.

The champions have suffered injury problems in defence during the first half of the campaign and could look to strengthen in that area after seeing their hopes of a third straight Premier League crown fade during the first half of the season.

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

Sunday morning's headlines:

Manchester City 'enter race for Jack Grealish'
Aston Villa captain Jack Grealish emerges as a transfer target for Manchester City, according to a report. Read more.

Flamengo forward Reinier 'set to undergo Real Madrid medical today'
Flamengo forward Reinier is reportedly set to undergo a medical at Real Madrid ahead of completing a transfer to the Bernabeu this month. Read more.

Manchester City 'in pole position to sign Houssem Aouar'
Manchester City lead the race to sign in-demand Lyon midfielder Houssem Aouar, according to a report. Read more.

Guardiola: 'Up to Leroy Sane if he wants to leave City'
Leroy Sane's future was the subject of much speculation last summer. Read more.

Manchester United 'interested in Kalidou Koulibaly'
Manchester United will reportedly move for Kalidou Koulibaly during the January transfer window, with Ole Gunnar Solskjaer said to be keen on bolstering his defence. Read more.