MADRID – American right back Sergiño Dest is set to join Barcelona, coach Ronald Koeman said on Wednesday.The Ajax player underwent a medical in Barcelona and the clubs were finalizing the details to make the transfer official, the Barcelona coach said.“He almost certainly will be with us,” Koeman said. “After all the contracts are signed, I have no doubt that he will be a very useful player for Barça."Koeman said the youngster will have to fight for a spot on the team but comes with the experience of already having played important matches with Ajax's first team, including in the Champions League.“I think that kind of experience will help the player but also will help the American national team,” Koeman said.The 19-year-old speedy defender.