After he scored as many as Chris Smalling that season, United unsurprisingly decided against spending the £43.5m it would have taken to make his arrangement permanent.
He left Manchester and sources close to the striker said he wanted to sign for Arsenal. He wanted to make it in England and London was the preferred destination.
Arsene Wenger dodged a bullet, Mourinho didn't.
He has one goal to his name in a blue shirt - a near-post header that wound up nothing more than a consolation because Chelsea lost 2-1 to Crystal Palace.
Against Swansea in a 1-0 loss two weeks ago, he made his first appearance since October, before going back to warming the bench in their following games against Manchester City and Bournemouth.
Yet he did make at least one appearance this week: in The Sunday Times Rich List.
In the 10 richest young sportsmen aged 30 and under, Wayne Rooney was No 1 with an £82m fortune, while down at No 7 was Falcao and his £29m kitty.
In the past year, Falcao's wealth increased by £9m via his wages and an endorsement deal with Puma. Since this time last year, he has scored a single goal for club and country.
Monaco's vice president, Vadim Vasilyev, thought about bringing him back in January but a calf problem saw that plan thrown out the window. He is living in limbo at Chelsea.
So what was it that Mourinho saw in Falcao that no-one else did?
The two share the same super-agent and, usually, what Jorge Mendes wants, Jorge Mendes gets. That's a suggestion being tossed around in some circles. Did that connection play a role in his coming to Chelsea?
Or did Mourinho by coincidence think he could conquer a challenge that had spectacularly fallen flat in Louis van Gaal's face? It's a guessing game.
What we know is there were only two options. Either a) Chelsea thought they could get out of him what Manchester United couldn't. Or b) he would follow in the footsteps of Fernando Torres.
Falcao was the man who put three past Chelsea in the 2012 Super Cup. He was the man who earned the nickname El Tigre for his predatory traits. He scored 41 goals in 51 league appearances at Porto, and 52 in 68 at Atletico Madrid.
To join Chelsea he took a 50 per cent pay cut but is set to leave in the summer - so just the £20,000 per day and £7,280,000 per year - even if his steady stream of Instagram snaps suggests he likes life in England.
Antonio Conte is unsurprisingly understood to be against keeping him, given it would cost £38m to make his move permanent, and Monaco will welcome him back, even if begrudgingly.
Once known as one of the world's greatest goalscorers, he had his injuries, but Falcao seems set to be the striker who just could not crack the Premier League.
- Daily Mail
