But the former Firhill favourite sees no reason why the Jags can't continue to defy the odds in the SPFL Premiership.
Alan Archibald's side are unbeaten in their opening three top-flight encounters and could quite conceivably be sitting with maximum points on the board after impressive performances against Dundee United, Ross County and Hearts.
The First Division champions have been in flying form so far and Thistle legend Rowson is confident they can shine on the big stage this season.
He said: "They had to carry the confidence they had from winning the First Division into this season. Hopefully things will continue.
"The last thing they would have wanted to do is lose all that confidence in the first few games. It has worked out great, so far so good.
"It is good for the boys to be confident but you can't be over confident. The bad thing about being on TV twice in the first three weeks of the season is that you lose that surprise factor.
"They have shown up well and it has given other teams a look at what they are about. They have maybe lost that element of surprise.
"But it has shown what a good passing side they are and hopefully they can continue to impress people."
Much of the credit for Thistle's terrific early season form goes to Archibald, with the Jags boss putting his faith in the players and the system that took his side to the title last term and believing that they could star in the top flight.
Rowson spent years trying to help the Firhill side over the First Division winning line and to a place amongst our elite.
The dream would be realised just months after he left to join Stenhousemuir, but the 36-year-old has no regrets after seeing his former team-mate lead the Jags to glory.
He said: "It was a hard situation for Archie. I spoke to him before he got the job and he had a lot to consider. Was it too early for him?
"But thankfully he took it and it has turned out well. He is very meticulous as a coach.
"He is looking at every aspect of the club, he has got people in looking at diet and strength.
"He is really going about things the right way. It is great that it is working out so well for him and long may it continue.
"We came close on two or three occasions but just never made it.
"Whether I would still have been able to do a job in the Premiership, who knows? It is one of those things.
"I can't have any regrets. I had some great times at Thistle. Leaving was a decision I had to make within two or three days.
"It has worked out okay for me and Thistle are doing well too, which is great to see."