Joe Nathan is not joining the Giants, at least not now. Nor are they getting a third catcher.
The club said Wednesday its September roster expansion will encompass six players. Outfielder Mac Williamson and reliever Josh Osich will come off the disabled list. Infielder Kelby Tomlinson will be promoted from Triple-A with left-handers Steve Okert, Matt Reynolds and Ty Blach, who will make his big-league debut.
All will be in uniform for Thursday's series opener at Wrigley Field, with Matt Cain to follow Friday when eligible to come off the DL.