Manotoc made his coaching debut during the 1977 Open Conference and immediately brought the Wranglers to a runner-up finish against Crispa, in the franchise's first finals appearance.

He admitted that besting Toyota in 1980, felt like an achievement since they were down by four points with 16 seconds remaining in the fourth, but ultimately forced overtime and won.

On July 1, 1984, citing health reasons, Manotoc resigned as head coach after leading the Redmanizers to the 1984 PBA First All-Filipino Conference finals, winning over NCC, 96–94.

After a long hiatus from coaching, Manotoc made a brief return to the PBA — in 1992 for the Presto Ice Cream Kings — and in 1997–1998 for the Mobiline Phone Pals.

A few decades later in June 2020, he revealed that during his championship stints as head coach of both U-Tex and Crispa, he did not charge the team, in terms of salary, and his bonuses that he had earned, were instead given to his father.