Jurgen Klopp's side, who finished as runners-up behind Manchester City in a tightly contested title race last season, will open the 2019-20 Premier League season against newly promoted Norwich City on Friday, August 9.
Schalke were due to visit the home of the Champions League winners on Tuesday, August 6, in what had been planned as the Reds' final pre-season outing.
Liverpool take in a Community Shield clash against City two days before, but the close fixture scheduling was not considered an issue.
However, the Norwich game has taken precedence, with a three-day turnaround deemed too tight for Liverpool to prepare for their opening match.
Liverpool and Schalke have confirmed they will attempt to rearrange the fixture for 2020, while the Bundesliga side have announced they will try to reimburse travelling fans who had already booked flights.
The Reds begin their latest round of pre-season fixtures with a trip to Tranmere on July 11, before hosting Bradford three days later.