Lassana Diarra is already proving a success at Marseille.
Lassana Diarra has had a strong start to life at Marseille, showing just what could have been at West Ham had the club been permitted to sign him.
The Hammers attempted to sign Diarra as a free agent earlier in 2015, but were denied by red tape.
Then boss Sam Allardyce told The BBC at the time: "After all the work we've done to get a player of his quality with a lot to prove would have been a huge bonus for us."
Diarra was able to move during the summer transfer window, signing with Marseille, amid a busy summer for the Ligue 1 side.
He has had a terrific start, with Maxifoot reporting he has been voted player of the month by fans of the club, amassing 35 per cent of the vote.
After going 14 months without playing a competitive match, last at Russian club Lokomotiv Moscow, Diarra's early performances have been a welcome surprise.
SkySports had even reported in February that Diarra was hoping the Hammers came back in for him this summer - something which could well have been a possibility had Sam Allardyce remained as manager.
West Ham were badly struggling for form in the second half of last season, and Diarra could have had a welcome impact had he been permitted to sign.
At Marseille though he has benefitted from a whole pre-season to adjust, rather than being thrown straight in mid-season.
Had West Ham made a move this summer, he likely would have been the alternative to Alex Song, who was re-signed on loan from Barcelona.
How the two players compare over the course of the campaign will measure whether West Ham made the right move, but so far the signs from Diarra have been that he would not have let them down had he been brought in.