Armas helped lead the Red Bulls to the 2018 Supporters' Shield and had a 29W-21L-11D in his time as an MLS head coach. He was an assistant at the club under Jesse Marsch then took over as the head coach when Marsch departed for RB Leipzig during the 2018 season.
Toronto have been without a head coach since Greg Vanney departed early this offseason. The club were reported to be interested in Laurent Blanc and Patrick Vieira, though Blanc accepted a job in Qatar a few weeks ago.
During his playing career, Armas was one of the league's best-ever defensive midfielders. He featured in 264 matches for the LA Galaxy and Chicago Fire FC while also earning 66 caps for the US men's national team.
Toronto fell just short of the Supporters' Shield this season and will be expected to be among the league's best teams again next year, led by reigning MVP Alejandro Pozuelo.