The January transfer window is a notoriously tricky time to do business.
But a packed fixture schedule, injuries, keeping up a title charge or fighting to stay up means several Premier League managers have hinted that they will need to go into the market this winter.
The January transfer window for English clubs opened on Wednesday, January 1 and closes on Monday, 3 February at 23:00 GMT.
BBC Sport has taken a closer look at five high-profile players whose futures are likely to come under scrutiny over the next month.
Sources said on New Year's Eve there had been an approach - but no offer - from Real Madrid about signing Alexander-Arnold in January, which Liverpool rebuffed.