The Undertaker is still said to be banged up from the concussion he received during his match with Brock Lesnar at Wrestlemania 30. Even though he's been working out, he has told those close to him that it's "not looking good" for Wrestlemania 31.
He's said to be in bad shape after his injury and his status for the event is unknown. A decision on whether or not he will compete won't be made until the end of the year at the earliest.
Credit: PWInsider via Wrestlezone