The Royal Blues have been on the lookout for a striker to play alongside star man Klaas Jan Huntelaar and general manager Horst Heldt announced this morning they have made progress in their pursuit of Szalai.
Heldt told Sport Bild: "Adam is with us for a medical after we reached an agreement with Mainz. It is just missing the contracts."
Szalai has reportedly negotiated a four-year deal with the Gelsenkirchen club and Heldt is excited at the potential of the 25-year-old.
"Adam has an incredibly good mentality and a good strike rate," Heldt said of a player who has netted 21 goals in 79 Bundesliga appearances for Mainz.
"We found last season we could not adequately replace Klaas Jan Huntelaar when he was injured.
"With Szalai we are taking the next step. Competition is very important."
Schalke finished fourth in the Bundesliga last season and will play in the qualifying rounds of the Champions League.