Miller, who played for Perth Glory, Brisbane Roar, and Melbourne City, had only positive things to say, which made O'Donovan very comfortable about accepting an offer to play for the Mariners this season.
O'Donovan was also well aware another countryman, Andy Keogh, scored plenty of goals for Perth Glory last season.
O'Donovan, 30, demonstrated his own confidence though, when he said he didn't need to know Keogh had done well, to be confident about his own chances of succeeding.
"Even if he hadn't been here it would have been my natural reaction anyway to believe I will succeed," O'Donovan said.
"But I'm always glad to see people I know do well and he had a great season last year."
Miller was the perfect adviser for O'Donovan, given he played 75 A-League games in his time here. He is now back home and playing for Cork City, in the League of Ireland Premier Division.
"I did my research and saw that Andy Keogh had done very well out here," O'Donovan said.
"I also had a good conversation with Liam Miller, who spent quite some time over here.
"I got a good idea from Liam about what it was like over here, what the clubs were like and how the league was progressing. I got a good idea of what I was stepping into and I haven't been let down by the information. I've been impressed so far.
"Liam said it was a good league, they play some good football and it's progressing all the time. And it was mainstream, all the games were on TV and the competition had a good fan base. He said the game was in a good place over here."
O'Donovan played for numerous clubs in England, including Sunderland in the Premier League.
Keogh, 29, played for many clubs in the UK as well. They played against each other in club football as well as together in the Republic of Ireland national team set-up.
O'Donovan also said he and his wife, Ellen, loved what they had seen of Australia so far.
"He's a good lad," O'Donovan said. "He's gone to Thailand now and I've come here after a season in Asia. I was looking for something more mainstream and it's a good step for me and my career."
"I've been in Australia now for a couple of months.
"The Central Coast is a beautiful place. Very quiet, beautiful beaches, and the Mariners is a good family club.
"There are some very good young players in our squad. There's a lot of hunger among the players and that could provide the basis for a good season.
"I'm very impressed with the location and the club and it's been very enjoyable. So far, so good."
Central Coast is badly in need of a striker who can score regularly, and O'Donovan has given the club good reason to believe he can fulfil that task with his early form in the pre-season trial matches.
He scored two goals in the first six minutes of a 3-1 win over Canberra club Gungahlin United last Thursday.
"We probably could have had a few more, but we kind of took our foot off the gas a little bit," he said.
"It was a decent week for us down in Canberra, with a couple of games and some good training. We got a lot of work done and everyone in the first-team squad got a game each and there were no injuries, so hopefully we can kick on in the next few weeks.
"We're still a work in progress. The pre-season is about working out combinations and building confidence. We've got a new team and we're getting the combinations and the rhythms right with each other and a new kind of system the team is playing.
"Come early October we should be ready and raring to go."
O'Donovan said he embraced the challenge of coming up with a good number of goals for his new club.
"I think that comes with the turf and it's the sort of pressure you come to know in this position from way back when you were a kid right through to playing professionally," he said.
"I'll be judged purely on goals by many people and I realise that.
"I fancy myself around the penalty box and if there are chances there to be sniffed at then I'm in there trying to finish them off. I'm out to score goals."
