Mainz have renewed the contract of first-choice goalkeeper Robin Zentner by two more years until 2025, the Bundesliga club said on Saturday. Zentner, 27, joined Mainz at age 11 and was only away for two years 2015-2017 on loan at Holstein Kiel. He has played 103 top-flight games for the mid-table club. “Robin is a true example of our ability to train goalkeepers from youth to first-team level,” sporting director Martin Schmidt said, adding Zentner “really stands for everything that Mainz does, in both a sporting and personal sense.” Zentner said: “I didn’t have to think twice when the club app…