Mullin, 35, is the leading appearance maker in Accrington's history and will come head-to-head with 37-year-old Alexander when Stanley host Burnley on Tuesday night.
And Mullin, who remains on the transfer list at the Crown Ground, is hoping both he and Alexander have a number of years left in them yet.
"The performances that Graham put up last season are a testament to him and the way he looked after himself," Mullin told the Lancashire Telegraph. "He played every game and was one of their best players. Age never came into it.
"He was playing like he was 10 years younger and, so long as he stays fit and healthy, there's perhaps a few more years left in him yet.
"There's no reason for me or Graham to consider hanging up the boots, so long as we are fit and contributing to the team. You are retired for a long time once you decide on it, so I want to keep on playing."