Matthijs de Ligt trained with Ajax on Monday despite his agent revealing the defender has come to an agreement with Juventus.
The Serie A champions are frontrunners to sign Ajax captain De Ligt, who has been linked with clubs including Paris Saint-Germain and Manchester United.
De Ligt's agent Mino Raiola confirmed on Sunday the Netherlands international has agreed personal terms with Juve.
But he was present for the start of pre-season training, with Ajax and Juve still negotiating over the transfer fee.
De Ligt is one of the world's most in-demand players having thrived in Ajax's run to the semi-finals of the Champions League.
His club and country team-mate Frenkie de Jong has joined Barcelona and they were also linked with signing De Ligt.