Thomas scored the two first-half goals which gave the Millers a 2-1 win at Swindon and put himself firmly in the frame for next Saturday's play-off semi-final tie against Preston.
With Kieran Agard and Alex Revell in good form, the journeyman striker, who played for Birmingham in last season's play-offs, has found it difficult to break into Rotherham's starting line-up.
But he made his point in the County Ground finale - impressing Evans in the process.
"Wes had a terrific game. He scored both our goals, but he also worked so hard - and does a lot of unselfish work for his team-mates, who simply love him," Evans said.
Thomas was withdrawn at half-time - but that was largely part of Rotherham's overall plan.
"He was substituted at the break as a precautionary measure. He was being antagonised on the pitch and, with the play-offs imminent, we didn't want anything untoward happening," Evans continued.
"The plan was for him to play for an hour and then give the other guys a run."
Thomas fired Rotherham into a first-minute lead and then doubled the visitors' advantage midway through the opening period - the influential Ben Pringle setting up both the goals.
It has set up a mouth-watering play-off tie with Preston and Evans is relishing the prospect.
He added: "No one gave us much chance of being in the play-offs when the season began - and now we're playing the side (Preston) who most people regard as the favourites.
"We're really looking forward to it. We'll dust ourselves down and go there well prepared.
"We've drawn twice with Preston this season - 0-0 at our place and a 3-3 draw at Deepdale in February, which was an epic match.
"The play-offs are a bit of a lottery, but once you're in them you take what you get.
"I've the greatest respect for Preston. They've got some top drawer players and a top manager in Simon Grayson, so it will be tough."
Rotherham enjoyed a stroll in the Wiltshire sunshine, going 2-0 ahead, but Swindon put them under the cosh in a 15-minute second-half window, clawing a goal back from a Michael Smith penalty.
"We needed a bit of pressure like that to prepare us for Preston next week, but to be honest we could have come here and won by a wider margin," said Evans, who rested several of his first choice players.
Source PA