The Billikens will play nine games on five dates in March and April as it prepares for the 2019 season.
Hein was taken in the second round and was the 48th overall pick. The selection comes on the heels of an impressive performance at last week's MLS combine.
Saint Louis freshman forward John Klein has been recognized by TopDrawerSoccer.com as a second-team selection on the Freshman Best XI.
Senior defender Lennart Hein has been invited to the MLS Combine, which takes place Jan. 3-9 in Orlando.
Boyce, Hein, Klein honored by United Soccer Coaches
Boyce, Hein, Klein honored by A-10
Freshman forward scored twice in the Billikens' 3-3 draw at Saint Joseph's
SLU knocked out of A-10 Quarterfinals by golden goal
Billikens and Patriots meet Sunday at 1pm (CT)
Billikens are No. 6 seed for A-10 Championship
Boyce and Niece score for Billikens
Denver upends Billikens 2-1