However, his appearances have since been sporadic. On the one occasion he did start, against Luton Town, he was replaced at half-time in a 3-2 defeat. His last appearance was as an 88th minute substitute at the end of March in another 3-2 defeat, this time against Plymouth Argyle.
He was an unused substitute on Saturday as York drew 1-1 with Wycombe Wanderers, a result that left the Minstermen nine points adrift of safety in their battle to avoid dropping down to the Vanarama National league.
Now 33, time is running out for Riordan, who is unlikely to stay at York beyond the season’s end. McNamara has urged him to take responsibility for his own actions and grasp the opportunities he is being given while he still can.
“It’s a frustrating one,” said McNamara. “Maybe like most people you hope you can try and help people and change them. It’s not about ability with Derek, it has never been about ability. There’s more there. Sometimes I wish I was in his shoes at his age with something there to give.
“But it’s trying to get him to see that sometimes, rather than look around and blame everybody else or different coaches or managers who haven’t given him a chance for the last ten years.
“It’s within himself to grasp it,” he added. “And as a manager and a coach and a person it is very frustrating to be on the outside looking in because a lot of us would give anything to go and do that again, even at his age.
“He’s 33, he’s still young, he still has another good three or four years in him, if he wants it.”