Coach Armas and highly-rated sports psychologist Lense are awaiting work visas ahead of becoming part of Rangnick's new-look staff but it was announced on Tuesday that both are coming to Old Trafford.
Lense was introduced to players at United's Carrington training base on Monday. The 46-year-old former midfielder previously worked with Rangnick at Schalke and Red Bull Leipzig but will have to wait for clearance on his visa before he can begin applying his well-regarded techniques to United's squad.
Manchester United have hired sports psychologist Sascha Lense (above) to help Ralf Rangnick
Lense (right) knows United interim boss Rangnick (left) from their time together at RB Leipzig
Armas, the 49-year-old former New York Red Bulls and Toronto FC coach, has also applied for his work visa ahead of being cleared to join up with Kieran McKenna and Mike Phelan.
Rangnick knows Armas from his work with Red Bull and has been looking to appoint up to three new coaches or analysts as he moves forward, particularly after Michael Carrick left United last week.
On his new recruits, Rangnick said: 'It won't be that many. I'm very happy with the staff I met last week and they gave me a lot of help in a lot of ways.
'We have decided to bring in a sports phycologist with Sasha Lense. He's was second division player when he played at RB Leipzig. We know each other since then and he will be introduced to the team as soon as he gets his visa and work permit tomorrow or on Thursday.
'I will also have another assistant coach in Chris Armas, who was the head coach at NY Red Bulls five years ago and we know each other. He will be able to join us in our team in the next two days.'
'Actually I don't know the situation in other clubs. In Germany most clubs has a sports scientist. For me it is absolutely logical.
'For me it is only a question of logic. Should have an expert for the brain. Not