The Dutch striker has been linked with a move to South Wales the last two summers.
The Dutchman has often been linked with a move to The Liberty Stadium.
"Castaignos is just one of a number of players we've been looking at of late."
A year earlier and again he was linked. The BBC again reported the news, claiming Swansea had a bid accepted for the player. In the end they signed Bafetimbi Gomis.
His name is forever cropping up during a slow news week for Swansea City so Swans fans will be happy to hear that a deal has finally been done, just not with Swansea.
Castaignos has finally made a long awaited move away from cash-strapped Twente and signed with German Bundesliga side Eintracht Frankfurt. The deal has been ratified and the German club confirmed the news on their official website this week. The 22-year-old has signed a four-year deal with The Eagles.
Castaignos, who has previously played for Feyenoord and Inter Milan, can finally stop being the go-to transfer rumour for Swansea.
At least, that is, for now.