The 31-year-old had an implantable cardioverter defibrillator device fitted after suffering a cardiac arrest while representing Denmark at Euro 2020, which saw him leave Italian giants Inter on a free transfer in December 2021.
Eriksen made the move to Brentford in January 2022, and a successful period saw the experienced midfielder score once and provide four assists in 11 appearances for the Bees.
Thomas Frank's side attempted to sign the Dane to another contract, but he left to join Manchester United, and he has represented the Red Devils on 34 occasions this season, scoring twice and providing nine assists.
Eriksen has just returned from an ankle injury which had sidelined him since January, featuring in his side's last three matches in all competitions, including a start against Nottingham Forest on Sunday.
Eriksen has now revealed his delight at being in a position to challenge for major trophies once again, having already helped Man United win the EFL Cup this term.
Erik ten Hag's side are also still chasing silverware in the Europa League and FA Cup, with the club facing a season-defining couple of matches in quick succession.
Man United will travel to Sevilla for the second leg of their Europa League quarter-final on Thursday, with the tie level at 2-2 from the first leg, before taking on Brighton & Hove Albion in the semi-finals of the FA Cup on Sunday.
"Looking back, a year ago, I was dreaming about where I am today," Eriksen told reporters during a press conference on Wednesday evening.
"Back then, it was just a dream of being back playing football and then of course taking it step by step and just being the best version of a football player you can be. And I was lucky at the time that the manager wanted me to come here.
"I'm enjoying it - I did a year ago, but I'm doing it even more now. To go as far as possible will be fun. And where we are now, already with a trophy, with aims for two more, it'll be good fun."
Eriksen also admitted that he was "surprised" that Reading forward Andy Carroll was not punished for the challenge that led to him picking up a long-term ankle issue.
"I was surprised he [Carroll] didn't get a yellow card," added Eriksen. "At the time I didn't think it was as bad so I didn't fear for the season. I was more concerned about when [in the season] I was going to be back.
"The medical staff have done very well, they've kept me in good shape and now it's like I never left so it's a positive for the medical staff."
Eriksen has provided two assists in seven Europa League appearances this season and will now be bidding to help the Red Devils progress to the semi-finals of the competition.