Berta arrived in Lisbon the day before for personal meetings with Sporting's directors to discuss the transfer fee for the Swedish player.
It has been reported that the agreed-upon fee with Sporting could reach up to £70 million. Previously, Gyokeres had agreed to join Arsenal, with a deal worth £200,000 per week in terms.
During the last season, Gyokeres scored an impressive 54 goals while playing for Sporting.
