The Evening Standard reports the deal is at an advanced stage, and there is no appetite at Old Trafford to let it drag on after news of Manchester United's surprise interest in the 29-year-old first broke on Monday morning. Fabrizio Romano reports Tielemans is already travelling north, with the first round of tests to follow ahead of him signing a long-term contract.
Tielemans is set to become the second midfielder through the door at Old Trafford this summer, following the £50m arrival of Andrey Santos from Chelsea. That deal was also wrapped up at speed once United had pulled the plug on a move for Atalanta's Ederson late in the day, even though a £37m package was already in place.
Michael Carrick has been left light in the middle of the park following the departure of veteran Casemiro, and Tielemans boasts 579 senior club outings, a level of experience the youthful United engine room has lacked.
The Belgian heads to Manchester on the back of an outstanding World Cup, where he was among his country's best performers before their quarter-final elimination by Spain. Both of his goals at the tournament came in the last-32 win over Senegal, while his displays in the group stage and the last-16 victory over the United States drew widespread praise.
Aston Villa, meanwhile, were powerless to stand in the way once the clause was activated, and now face a scramble to rebuild their own midfield. Unai Emery had already lost Amadou Onana, Tielemans' Belgium team-mate, to an ACL rupture at the World Cup, leaving the position in urgent need of attention at Villa Park.
For United, though, the week has brought rapid and decisive progress. Having watched the Ederson deal unravel, Carrick has moved swiftly to secure a proven Premier League operator, and supporters could see both of the club's new midfielders unveiled before pre-season moves through the gears.