Ajax’s deep sporting crisis continued on Thursday with their first ever Dutch Cup exit against an amateur club. The 20-time KNVB Cup winners lost 2-3 in extra time at fourth division club USV Hercules in the second round of cup. Brian Brobbey and Chuba Akpom cancelled out a 2-0 deficit late on in Utrecht with goals in the 83rd and 88th minutes, but Mats Grotenbreg scored the winner for the underdogs in stoppage time to complete the upset. “That shouldn’t have happened,” said Ajax assistant coach Michael Valkanis after the match. He was standing in for head coach John van ‘t Schip, who is in Au…