The Mad Men star recently completed a stint in rehab to address his drinking problem, but made a return to the spotlight this month (Mar15) for a number of glitzy events to promote the last series of the hit drama show.

However, he has been forced to walk the red carpet alone because his longtime girlfriend Westfeldt has been dealing with drama of her own.

A representative for the actress tells New York Post gossip column Page Six, "Unfortunately, Jennifer was not able to attend (the events) because of a serious illness in her family, on the heels of a recent death in her family."

The couple has been together since 1997.