When Lubin grew up to a height of 6 ft 7 in (2.01 m) at Lincoln High School, classmates encouraged him to try out for the basketball team. Gangly and uncoordinated, Lubin struggled to improve his game, but was eventually named to the All-City Second Team as a senior in 1927.[3]
During the 1936 Summer Olympics, Lubin was invited to come to Lithuania, and he became their first national team head coach. They won the EuroBasket title in 1937, using American-born players of Lithuanian heritage.[5] When the team hosted the EuroBasket in 1939, they again won the title, this time with Lubin, acting as a player-coach. Lubin the de facto MVP of EuroBasket 1939, however he was unable to receive the award, because he was taller than 6 ft 3 in (1.91 m), and FIBA had a rule at the time, which prohibited the award to be given to players at such a height.[6]
When World War II broke out in 1939, Lubin was in Italy, coaching a Lithuanian women's team. Given that Nazi Germany was directly on the path back to Lithuania, Italian officials had to help the team to get back, through train and boat, avoiding Germany.[3] Afterwards, Lubin fled Lithuania to California with his family, in the face of the upcoming Soviet invasion that happened one year later.[5] Lubin continued to play for the 20th Century Fox team until 1955, when knee problems prompted him to retire. For his contributions and for introducing the now basketball-mad country of Lithuania to the sport, Lubin is often called the "grandfather of Lithuanian basketball".[3][7]