The Hammers signed the striker for a fee of £45m in the summer of 2019 from Eintracht Frankfurt, but he has struggled in England and is on his way out after just 18 months at the London Stadium.
Ajax have agreed a deal with West Ham for Haller and are now putting the finishing touches to the signing of the former FC Utrecht man.
West Ham are taking a loss on Haller, but Fjortoft, who watched the striker play in the Bundesliga on a regular basis, is still convinced of his quality.
The Norwegian thinks that the move to West Ham just did not result in success for the striker.
Fjortoft took to Twitter and wrote: “The West Ham striker on his way to Ajax.
“I rate the former Eintracht Frankfurt player, but for some reason, it didn’t work out in England.”
Haller netted just 14 goals in 53 appearances for West Ham and will look to rediscover his goalscoring form in the Dutch top flight.
