It was announced before last night’s WWE live event in Oakland that John Cena would not be able to make it. Justin Roberts offered refunds to fans.
This led to Big Show making his return to the ring. He defeated Rob Van Dam, Ryback, Justin Gabriel, Curtis Axel, Mark Henry, Wade Barrett, Christian, The Usos, The Miz and The Shield in a battle royal to earn a shot at Alberto Del Rio later on. Show ended up beating Del Rio by DQ when Del Rio used a steel chair.
Source: Prowrestling.com
So apparently the story is that Cena was seen in the Bay Area earlier that day, but no showed the event. It is still unknown why Cena wasn't there. Seems like it wasn't expected though because it sounds like from recent reports that Big Show wasn't read to return but due to Cena not being there, they had to pull something out and Big Show had to work.
Wonder why he wasn't there, and if this means Big Show will be back on TV soon. Also find it weird that WWE offered refunds for ONE guy being gone. Granted he is the top star, but don't they put out a disclaimer saying that the card is subject to change?