Tim Lincecum (back) will undergo an MRI on his lower back Thursday, John Heyman of CBS Sports reports.

Lincecum (back) will undergo an MRI on his lower back Thursday, John Heyman of CBS Sports reports.

Analysis:

Lincecum departed Wednesday's Game 2 loss in the eight inning after throwing a pitch and feeling tightness in his lower back. The MRI will ultimately determine his status going forward, but it's possible he could be replaced on the roster if the injury turns out to be anything serous. George Kontos, Juan Gutierrez and Erik Cordier could all be potential replacements if Lincecum does, indeed, need to be replaced. For what it's worth, manager Bruce Bochy was encouraged by how Lincecum threw -- he retired all five batters he faced -- and said after the game that he "[thinks] he'll be fine."