Jason has had an uneasy relationship with his father and is untrusting of Tony's grand plans for the future as he has been let down before.
But Ryan Thomas, who plays Jason, said his character's usually absent father could be about to shake the Grimshaw family.
"Jason was very surprised when his dad turned up," the actor explained.
"He has been here before very briefly and he didn't put much effort in with Jason, so Jason sort of gave up on him. He has kept in contact with him on the phone, but apart from that he has not really been much of a father figure.
"I wouldn't say Tony isn't the best dad in the world, but he has his son's best interest at heart.
"In one sense, you might look at him like he is a bit of a rogue, a bit of a bad lad, but he still has a real soft spot for Jason.
"So he turns up again and I think Jason secretly enjoys the attention from his dad. I don't think he wants anyone to know and he is putting up a bit of a defense with him and he is trying to push him away, but he keeps coming back."
Finally relenting to his dad's wishes to spend more time together, Jason invites Tony to his brother Todd's birthday party, though this might not go down well with mum Eileen.
"Eileen is not so happy about the situation because she has got a lot to deal with now, with Todd and the uproars he has caused in the family.
"And then you've got another sneaky character like Tony walking in the door."
And the actor hinted that Tony's arrival could bring trouble for the Grimshaws as they don't know what they are in for.
He added: "It is exciting, but you are left in the dark a lot of the time with Tony, so I think, for the Grimshaws, it is going to be a lot of letdowns plus a lot of trouble and a lot of heartache for everybody around Jason and the rest of the family."
Coronation Street airs on UTV every Monday, Wednesday and Friday from 7.30pm.