Sampaoli, formerly of Chile and Universidad de Chile, has long been linked with taking over at the Albiceleste helm.
Those reports have only intensified since Edgardo Bauza was sacked shortly after Tapia was chosen as the AFA chief, with the president himself forced to deny he offered Sampaoli the job during a recent visit to Europe.
Speaking on Thursday, however, Tapia affirmed that there was no other candidate but Sampaoli currently under consideration.
"We are going to negotiate Sampaoli's exit [from Sevilla]. He is the chosen one," he explained to ESPN.
While talks between the parties have not yet taken place, one close Sampaoli collaborator is convinced the Rosario native's return to his home nation is a done deal.
Sebastian Beccacece, his assistant with Chile and current Defensa y Justicia coach, has been slated as Sampaoli's potential No. 2 should he take up the Argentina job.
And there is no doubt in his mind that the Sevilla man will soon be directing the likes of Lionel Messi and Sergio Aguero, even if he was not as certain on his own future.
"I have asked [Sampaoli] for some time to think over the offer he made me with the national team," Beccacece told Jogo Bonito.
"It is not my place to talk about Argentina players because I have a firm offer from Sampaoli. I spoke to him two days ago and he asked me about my contract.
"We had not spoken for a long while, I have not made up my mind yet. I have some big games with Defensa."
While his future will remain uncertain until the end of the season, Sampaoli and Sevilla took another big step towards the Champions League on Wednesday with a 2-1 win over Celta.