Barcelona winger Pedro has flown into London to conclude a deal worth £21.1m to join Chelsea, Sky Sports News HQ sources understand.
Sky Sports' La Liga expert Guillem Balague says negotiations between Chelsea and Barca began as late as Tuesday but were concluded swiftly and Pedro is likely to undergo a medical in the capital on Thursday.
The Premier League champions had expressed an interest in the player for more than a week, but unlike Manchester United and Manchester City, had not placed a bid.
United claim they had the option of signing Pedro earlier in the window but, after long consideration, manager Louis van Gaal decided to end their pursuit of the player.
Balague earlier reported that Pedro had agreed personal terms with United and that the 28-year-old was just waiting for the clubs to agree on a transfer fee.
United's chief executive Ed Woodward is understood to have visited Barcelona for talks but it is believed the European champions would not budge from the release clause, which was never met by United.
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Barcelona were keen to keep Pedro and offered him a new contract, but they could not give him the assurances he needed over regular first-team football and he has sought a move away from the Nou Camp.
Van Gaal said on August 14 that the ball was in Pedro's court only to eventually decide against the deal.
Balague said: "United do not want to pay what Barcelona want because Van Gaal decided, despite contact with the player, that he was now not needed."
Pedro has featured in Barcelona's three most recent games in the UEFA Super Cup and the two-legged Spanish Super Cup, which they lost to Athletic Bilbao.
But they beat Sevilla 5-4 after extra-time to clinch the UEFA Super Cup on August 11 with Pedro scoring the winner.