Cooper comes from a footballing family. One of his brothers, Kevin Molina, is headed to London as part of T&T's Olympic squad. He grew up playing football as well but was persuaded by his father, a cricket fan, to switch his allegiance. When Cooper was picked for the T&T Under-19 squad, he left football behind.
In January 2011, cricket officials raised concerns over Cooper's bowling action, and he went to the University of Western Australia to undergo tests and undertake remedial work to correct the fault in his bowling action. In August 2011, Cooper was cleared to play.
He returned and participated in the Champions League in 2011. Mixing speeds with his medium pacers to good effect, he took five wickets in six games while conceding just 5.29 runs an over. Coming in at No. 7, he posted a strike rate of 191.17 at an average of 21.66. It was these attributes that drew the attention of the Royals, who bought him for $50,000 in the IPL player auction.