Schweinsteiger, 32, agreed a move to Major League Soccer this month after a difficult few months under Jose Mourinho, who sent him to train with the reserves after taking over at United last summer.

The former Germany international had spent his entire career with Bayern Munich before joining United, then managed by Louis van Gaal, in 2015 and he said last summer: "MUFC will be my last club in Europe. I respect other clubs, but Manchester United was the only one which could make me leave Bayern Munich."

He has now said that he was motivated by the prospect of playing "one more time at Old Trafford" before he left, not wanting to end his United career on such a low point, and he ultimately forced his way back into the first-team reckoning in November despite the club having previously written him off as an asset. 

He ultimately made four appearances under Mourinho, the first in a home EFL Cup win over West Ham on Nov. 30 and the last in Feb. 22's Europa League win away to St Etienne. On Jan. 29, he scored in the 4-0 FA Cup win over Wigan at Old Trafford.

"My dream came true," he said.

Bastian Schweinsteiger made three Old Trafford appearances under Jose Mourinho, scoring against Wigan.

He remained highly positive during his United exile and says: "I'm not really a negative thinker. It was a character test, that's all."

He added: "Even when I was training alone, just me and one of United's fitness coaches, I loved going onto the field, doing sprints, being at the training ground."

He gave little away on why Mourinho restored him to the first-team squad.

"The manager came to speak to me," he said. "He told me something -- it is not my job to say what that was -- and then I was training with the first team."

He said he "never doubted" his quality and is determined to "prove something" to himself with the Fire, and is excited about the chance to play in MLS.

"I remember when Bayern came for the All-Star Game in 2014," he said. "My brother was with the first team then, too, and we sat on the bench and said how great the atmosphere was. It really felt like an event."

He also praised Fire head coach Veljko Paunovic, comparing him to one of his former Bayern bosses.

"He reminds me of Pep Guardiola in how he wants his team to play and his ideas for the game," he said. "I was really impressed."