The former Manchester United, Stoke and Wales wide-man made the claim ahead of Friday night's 2014 World Cup qualifier at Hampden Park.
The Scots are bottom of Group A with two points from four games, one behind Chris Coleman's men who won 2-1 when the two countries met at Cardiff in October.
Ahead of the return game in Glasgow, Thomas was quoted as saying: "Let's make no mistake about this - this Scotland team is the worst they have ever had."
Asked if the Scottish players would use those comments as motivation, Stoke City midfielder Adam, speaking at the national stadium, replied: "We will. That's up to him, it's his opinion.
"We will take that on the chin. That's what Mickey is like and I know him quite well with him coming into Stoke so I will have a word or two with him when we get back.
"That was probably a little bit of kidology but we are ready for it, we have good players in the squad.
"It is about us, we don't need to worry about what other people are saying.
"It is going to be a tough game but we are looking forward to it."
When the former Rangers, Blackpool and Liverpool player walked into the media conference there was already an elephant in the room in the shape of Gareth Bale.
Both players had clashed on a couple of occasions with their clubs before the Tottenham superstar left Adam in his wake in Cardiff to fire in a long-distance drive which gave the Welsh a last-gasp win.
The Dundee-born playmaker bore the brunt of the criticism for the defeat in Wales but when the issue was raised the 27-year-old said: "That's your opinion. That's everyone in the press, they sell the papers and that's the way it goes.
"I deal with it internally, that's the way it is.
"The lads take the criticism that we got, fair or unfair, that's done and dusted, it's gone now.
"It's a different game and a different challenge for us, we are ready and hope we can get three points.
"I thought we were okay until a certain stage in the game in Wales.
"We got a disallowed goal that should have been a goal and that changes the game. That was hard for us to take.
"They got a penalty that probably was a penalty and he (Bale) had a wonder strike that went into the top corner, that's what happens."
Adam acknowledged Bale's quality and form but insists the Spurs forward is not the only threat to Scotland - who will have manager Gordon Strachan at the helm for the first time in a competitive fixture, following the 1-0 win over Estonia in their challenge match at Pittodrie last month.
"They have other players, they are not just a one-man team," he said.
"Real Madrid and Barcelona are not one-man teams, you have other players that are top players who play in the Premier League.
"People keep saying it's about Gareth Bale and he is up there, one of the best in the world at the moment.
"He is a top player and we will probably have a plan to stop him but they have other good players.
"It doesn't matter if we stop him or he has an off-night, it doesn't mean it will be an easier game for us."
Adam promised the Tartan Army that they will see a Scotland team going all out to rescue their fading qualification hopes before the second of the double-header in Serbia next week.
"We have to go for it, we are not in a good position and if we want to do something then we better start on Friday night," he said.
"We are a better team (than the points total suggests) but we are the only ones who can fix it.
"We will need to attack and we will do.
"It is a challenge. Everyone in Scotland thinks we can win, the players think we can win but it is going to be a tough match."