As a senior, he averaged 16.7 points and 7.0 rebounds per game for head coach Eugene Richardson.

Gaines helped lead Boyd Anderson to a 30–2 record, eventually losing in the Florida 6A State Final.

He hit at least one three-point basket in 24 of 30 games on the year, including a season-high five at home against Oral Roberts on February 15, 2012.

On November 1, 2013, he was selected by the Maine Red Claws with the 1st pick of the second round in the 2013 NBA Development League Draft.

[4] On April 7, 2014, he signed with Gigantes de Guayana of Venezuela for the rest of the 2014 LPB season.

[11] On February 27, Gaines joined the Oklahoma City Blue after the team acquired his returning player rights from the Maine Red Claws.

[18] On July 18, 2019, he has signed with Virtus Bologna of the Italian Lega Basket Serie A (LBA).

[21] Cantù ended the season in the last position and Gaines signed with Scafati Basket for the 2021 Serie A2 playoffs.

[24] On February 13, 2023, he was released by Trieste and signed with Fos Provence Basket of the LNB Pro A.