He played in Major League Baseball (MLB) for the Minnesota Twins, Tampa Bay Rays, and San Diego Padres.

[6] When on the Twins, Bartlett was one of four players known for speed and small ball, nicknamed "the Piranhas" by Chicago White Sox manager Ozzie Guillén.

On November 28, 2007, the Twins traded Bartlett along with Matt Garza and Eduardo Morlan to the Tampa Bay Rays for Delmon Young, Jason Pridie, and Brendan Harris.

[7] Bartlett finished the season batting .286 with one home run, and was voted by local Tampa sportswriters as the Rays' MVP for the year.

On December 17, 2010, Bartlett was traded to the San Diego Padres for Adam Russell, Cesar Ramos, Brandon Gomes, and Cole Figueroa.

On the same day, his fellow middle infielder Orlando Hudson was released and the Padres brought up Everth Cabrera and Alexi Amarista in corresponding moves.