Last August, Borussia Dortmund supporters launched a viral campaign urging Manchester United to allow Shinji Kagawa to leave Old Trafford.
#FreeShinji was the hashtag - and it spread across Twitter like wildfire.
United supporters reacted defensively. Although the Japan international had endured a tough debut season in England, fans had seen enough glimpses of his quality to know they had a player with massive amounts of potential on their hands.
One case in point was the attacking midfielder's sublime hat-trick against Norwich City. Kagawa would produce similarly effective performances on an almost weekly basis at Signal Iduna Park, where he flourished under Jurgen Klopp, so why was he struggling to do the same in England?
Injuries certainly haven't helped United's £12m signing, while Sir Alex Ferguson and more recently David Moyes have on occasions deployed him in his unfavoured left-wing position - but rather than progress, if anything the playmaker has regressed this season, even when he's played at No. 10.
Last night, in the Capital One Cup semi-final second leg against Sunderland, Kagawa produced a bitterly disappointing performance - and not for the first time this season.
When Moyes needed his so-called star names to stand up and be counted, Kagawa has so often disappointed.
This, you suspect, is one of the reasons why Moyes has agreed to play a club record £37m to Chelsea for Spanish playmaker Juan Mata.
Mata is a similar age to Kagawa and plays in the same position - so where does this leave the Japanese star?
Eighteen months after signing for the Red Devils, it seems increasingly likely that Kagawa's move to Old Trafford is not going to work out as planned.
He looks totally bereft of confidence and a shadow of the player Ferguson watched light up the Bundesliga before bringing him to the Premier League.
And seeing the club's new record signing - all going to plan - walk into Carrington on Friday morning is unlikely to do his confidence much good as this season's pivotal months near ever closer.
Klopp is a keen admirer of the Japanese midfielder, so perhaps Moyes could tempt the Dortmund boss into selling either Ilkay Gundogan or Marco Reus for a cash-plus-Kagawa offer in the summer.
It's hard to envisage Manchester United supporters ever seeing the real Shinji Kagawa at Old Trafford.
And for that reason it could be them launching their own #FreeShinji viral campaign in the not-too-distant future.