Manchester United is about to complete an agreement for Sporting Lisboa midfielder Bruno Fernandes.
The Old Trafford club has been negotiating with Sporting during the entire transfer period, but refused to reach an initial price of 80 million euros (£ 68 million).
But a breakthrough in the negotiations on Tuesday left United confident of reaching an agreement for the 25-year-old.
The initial rate will be around 55 million euros (£ 47 million), but the supplements could increase the total cost to 80 million euros.
If the agreement is finalized, it will be the largest transfer window for January in the Premier League so far.
United manager Ole Gunnar Solskjaer has prioritized the midfield as an area to strengthen this month.
Fernandes joined Sporting de Sampdoria for £ 7.2 million in 2017.
He has scored 64 goals in 137 games in all competitions and won the Portuguese Cup in 2018-19. He was also named Primeira Liga player of the year in both 2017-18 and 2018-19.
He played 19 times for Portugal and was part of the team that won the UEFA League of Nations.