He started his professional career in the Northern Hemisphere in the autumn of 2009 with Lietuvos Rytas, a club from Vilnius that competes in the Lithuanian league and Euroleague.
From the autumn of 2010 he played for the German Eurocup team EWE Baskets Oldenburg.
Following his season in Germany, Baynes signed with the Greek team Ikaros Kallitheas B.C..
On 1 August 2012, Baynes signed with the Slovenian club Union Olimpija. He left Olimpija in January 2013.
On January 23, 2013, Baynes signed with the San Antonio Spurs. In his second NBA game, Baynes recorded 7 points, 9 rebounds and 1 block in a 102–78 victory over the Charlotte Bobcats. The Spurs assigned him to the Austin Toros of the NBA D-League several times over the course of the season. Baynes made his first NBA career start in Game 4 of the first round in the playoffs against the Los Angeles Lakers, and was tasked to defend Dwight Howard.
|GP||Games played||GS||Games started||MPG||Minutes per game|
|FG%||Field goal percentage||3P%||3-point field goal percentage||FT%||Free throw percentage|
|RPG||Rebounds per game||APG||Assists per game||SPG||Steals per game|
|BPG||Blocks per game||PPG||Points per game||Bold||Career high|
NBA regular season
|2013 NBA Playoffs||San Antonio||4||1||5.8||.571||.000||.000||1.3||.0||.0||.0||2.0|