Tottenham have announced the signing of Gedson Fernandes on an 18-month loan deal from Benfica.
The 21-year-old has been handed the number 30 shirt at Spurs, who will have the option to make his move permanent at the end of the 2020-21 season.
Fernandes expressed his delight after completing a move to north London, stating: "It's one big dream to come to this big club."
The Portugal U21 international could be in line to make his Tottenham debut when they take on Watford at Vicarage Road on Saturday.
After rising through the youth ranks at Benfica, Fernandes graduated to the senior squad in 2018, before establishing himself as one of the brightest young prospects in the Primeira Liga.
He has already racked up 43 appearances across all competitions for the club, with 22 of those coming during their title-winning run last season.
Fernandes will now be expected to help Tottenham rediscover a consistent streak, with a lack of depth across the middle of the park costing the team valuable points in recent weeks.
Moussa Sissoko has undergone surgery on a serious knee injury which is likely to keep him out of action for an extended period, while Tanguy Ndombele is still unavailable due to a hip issue.
Meanwhile, Christian Eriksen has been tipped to complete a move to Inter before the winter transfer deadline, with Mourinho urging the playmaker to "leave with his head held high".
Fernandes is a box-to-box midfielder by trade, and could inject much-needed energy in Tottenham's starting XI heading into a crucial period.
Mourinho's side will be desperate to beat Watford to stay in the hunt for a top-four finish come May.
Spurs have already slipped to eighth in the Premier League table after 22 fixtures, nine points adrift of Chelsea - who currently occupy the final Champions League spot.
After their clash with the Hornets, Tottenham will look ahead to a meeting with Norwich on January 22, before taking on Southampton at St Mary's in an FA Cup fourth-round tie three days later.