By Chelsea correspondent Tony Hughes | Premier League expert with experience of breaking big stories, including exclusives like this
Matt Miazga began a Chelsea medical on Thursday as he closed in on a move from New York Red Bulls, Football Insider sources understand.
The Premier League champions have agreed a fee of £2million plus £1.5million of add-ons for the US international.
Football Insider revealed on Wednesday that Chelsea were in advanced talks to sign the centre-back after he was given permission to fly to the UK to finalise the deal.
The USA international, who has just a year remaining on his Red Bulls contract, has been closely monitored by a number of Premier League teams over the last six months and he is now set to complete a move to Stamford Bridge.
Chelsea freed up space in their squad by loaning Senegal international Papy Djilobodji to Werder Bremen for the rest of the season.
Miazga has been with the USA squad preparing for upcoming friendly matches against Iceland and Canada but there are reports he has left the training camp to head to England.
Given that he also holds Polish nationality, Miazga will not need a work permit to move to the Premier League.
The defender joined the Red Bulls academy in 2009 and rose through the ranks to become a mainstay of the team under manager Jesse Marsch.
In other Chelsea transfer news, Alexandre Pato is closing in on a move to the Bridge after undergoing a medical at the club on Wednesday afternoon.