Having tracked Thomas, 28, over a protracted period before bringing him from Melbourne Victory to southern Jutland three months back, Riddersholm is convinced he has a gem in his midst.
Thomas has already won SønderjyskE’s player of the month twice and been named in five Danish Superliga team-of-the-weeks.
Riddersholm sees no limit to how far the former youth international can go, potentially joining the likes of Mat Ryan, Mitch Langerak and Andrew Redmayne in the senior ranks.
“I don’t know the situation with goalkeepers in the national team but if Lawrence isn’t among the three best then Australia must have some very good goalkeepers,” said Riddersholm.
“Here he’s come into a team that’s well structured defensively and that’s made it easier for him to show his best and perform at the top of his level.
“I can’t tell Australia how to pick their team and I totally respect whatever they do.
“I can only recommend him in a positive way, and say what a positive impact he’s made here.
“The federation are always welcome to call me if they need any kind of information.
“I’m sure they can see what he’s bringing and it’s up to them to make the right decision for them.
“Whatever happens Lawrence will respect their decision and so will I because in football you can have different types of views.”
Thomas - on the books of Sheffield United as a teenager - was handpicked to replace German Sebastian Mielitz, with Riddersholm explaining: “We knew Sebastian was leaving and we needed to find somebody for the future.
“Thomas was at the top of our list for quite a while because he had a lot of the attributes we were looking for.
“At my former club Midjyland I knew Jakob Poulsen, who played with Lawrence in Melbourne and I wanted to know what he was like as a person.
“For me, it’s not only important we have a good player but also somebody who can adapt to the culture here and how it is in the locker room.
“Jakob was my former captain and he spoke very positively about Thomas and after analysing a lot of games and doing all the research we were not in doubt about going for him.
“From day one, he’s shown character, personality and great humour.
“He’s excellent off the pitch as well as on and that’s really good for the culture and mentality we have here.
“He’s humble but very ambitious and I’m sure there will be interest from bigger clubs in bigger leagues if he can maintain this level.”
Riddersholm’s wish list was a keeper who was as good at claiming crosses and commanding the 18-yard box as he was with his feet.
And he feels Thomas ticks all those boxes.
“Previously Sebastian was very good for us but we sometimes missed dominance in the box and Lawrence brings that,” he explained.
“He’s produced saves which have earned points.
“Last season we dominated many games but missed too many chances and the first opportunity the opponent got they would often score.
“If you put it all together you can say he’s had a really good entrance into the Danish league and our club.
“A lot of people all around the competition are talking about Lawrence at the moment.”
SønderjyskE lead the ladder by a single point, but Riddersholm admits with the club’s modest budget means it will be tough to stay there.
“It’s a surprise really because we are a club with many steps to take,” he said.
“It’s a good challenge to move the club forward. I’ve been here nearly two years (having previously piloted Midtjylland to their maiden title) and the project here is interesting.
“I don’t think we’ll be number one when the season is over but we’ve had a really good start.”
Riddersholm previously worked with Socceroos Chris Ikonomides at Midtjylland and Mustafa Amini at AGF, and likes the dedication to the game shown by Australians.
“They’re open-minded like the Danes and I like their professionalism and focus,” he added.
