Kelly left Saturday's game because he was feeling lightheaded, Michael Silverman of the Boston Herald reports. He's still being evaluated.
The hard-throwing right-hander was not experiencing any chest pains, according to Christopher Smith of MassLive.com, but the Red Sox will continue to monitor Kelly to be sure he's OK. If this issue were to cost Kelly additional time, Matt Barnes would presumably move up and take on primary setup duties in front of closer Craig Kimbrel.