The Everton winger arrived on a season-long loan on deadline day having been told he is surplus to requirements by new Toffees boss Ronald Koeman.
Having starred as he came through the ranks at Celtic before sealing a move to Spartak Moscow, McGeady has seen his career stall over the last 12 months.
The Republic of Ireland international finished last season on loan with PNE’s Championship rivals Sheffield Wednesday but was not a regular as they missed out narrowly on promotion to the Premier League, losing in the play-off final to Hull City.
Grayson believes however that McGeady can be a key man for North End after his surprise move to Deepdale.
The PNE boss knows the Irish set-up well, having played under manager Martin O’Neill and alongside coach Steve Guppy while at Leicester City, and has been impressed with what he has heard.
Grayson said: “I spoke to Steve Guppy who’s working with Ireland about Aiden and he said it was a good fit for both him and us.
“We’ve had a lot of players over the last three of four years come to the football club who haven’t been wanted by other clubs.
“Jermaine Beckford and Joe Garner weren’t firing when they came us. We’ll work hard with him to get him back to where he once was.
“It’s our job as coaches to keep on trying to improve the players.”
The move, confirmed less than two hours before the summer window shut, saw 85-cap McGeady miss Robbie Keane’s final international against Oman.
That dedication impressed many at Deepdale, while on the field Grayson believes the 30-year-old will bring something of an ‘X factor’ to his side as they look to improve on a stuttering start that has seen PNE win just one of their opening five Championship games.
Grayson said: “He’s had a fantastic career with the clubs he’s played for.
“Pulling out of Robbie Keane’s final international shows how determined he was to get it done.
“He gives us something different – he’s someone who can create something out of nothing and he fits within our budget.”