Shinji Kagawa has wasted no time showing Manchester United fans exactly what they were missing now that he has returned to Borussia Dortmund.
Kagawa's time at Old Trafford was unpredictably disappointing and he returned to the club that he made his name this summer.
Since his reunion with Jurgen Klopp, Kagawa has slotted back into top level football with ease and it has left many United fans querying why he couldn't find his top form in England.
A creative, skilful attacking midfielder, Kagawa is one of the key points of Dortmund's attack, but he rarely threatened defences in the Premier League.
Often used out wide, Kagawa struggled to settle, but even when moved into a more favoured central position he couldn't find his top form.
As a result, his return back to the Bundesliga was not unsuspected, but the ease of which he has raised his game has been a frustration for fans of the Red Devils.
Kagawa was pulling the strings again as his Dortmund side beat Anderlecht in the Champions League, picking up two assists, and United fans were annoyed by the display on Twitter.
This was the sort of performance that they had been expected to witness from the Japanese international whilst he was at their club, but instead they had to view it from afar and it created some interesting reaction on the social media site.
Here are the best of the responses to Kagawa's display.
Kagawa spent 2 seasons at us & still found time to say thanks. Welbeck was there from a kid & didn't say nothing. That shows a lot. #mufc— Kymani (@dhinds819) October 1, 2014
So welbeck scores a hat trick in champions league and kagawa looked unplayable for Dortmund sommat not Reyt somewhere down line here #MUFC— king eric (@AdeHickling) October 2, 2014
Welbeck and Kagawa proved tonight that United always had the quality players, Moyes and LVG just clueless to how to use them. #mufc— AEssof (@AEssof05) October 1, 2014
Just seen Kagawa dominate the Dortmund highlights. Class act and a shame he was never given a proper go at #MUFC— An_dre88 (@an_dre88) October 1, 2014
Good assist from kagawa too knew he would start doing stuff like that after he leaves #MUFC— Scott Grassick (@scottgrassick) October 1, 2014
Welbs hattrick & Kagawa proving how good he is tonight, we've still got Anderson.. yeah, the last transfer window was a total success #MUFC— Ram™ (@Ramfiki) October 1, 2014
Kagawa looked decent tonight. It's a shame he wasn't given a full run in our team. #MUFC— Tom Campbell (@TomCampbe11) October 1, 2014