Although the two red cards in his first three games for the Hammers were debatable - both times for two bookable offences rather than one serious one - he knew that he had to modify his approach if he was to be able to maximise his contribution to the club.
"He understands that we need him and if he receives yellow cards we will lose him for a few games, which we don't want," says Ludek Miklosko, who acts as an interpreter for Tomas and Vladimir Labant until they master the English language.
"Sometimes he was getting booked not for fouls but kicking the ball away and talking to referees - quite silly things.
"But he has changed and we can see it has made him a better player."
Tomas, whose style was likened by Ludo to Julian Dicks when he came, has been booked just three times in his last 12 games.
Ludo's other charge, Vladimir Labant, had a less happy afternoon on Monday, having to leave the field in the first half following an awkward fall.
He was in the side to give a rest to Nigel Winterburn, who had played on the Saturday, and will be available again at the weekend for the derby game with Charlton.
"He went for the challenge and landed on his back," says Ludo, "and he had a spasm so it was very painful. "He wanted to play on but he just couldn't move his left leg.
"But I think Tomas played well, the whole team was solid, and defended well; it was a very important win and the whole team played with confidence - and it was very good.
Ludo expects even better things from the pair next season once they have learnt the language more and both enjoyed a pre-season with West Ham.
Vlado joined on the back of a midwinter break with his former club Sparta Prague, while Tomas came early in the season from Fiorentina and was pitched straight into the thick of things.
But, come July 1st when West Ham report back - apart from those on international duty - they will both begin preparations for a full English season.
Says Ludo: "Vlado needs a pre-season. When he came here he just tried to pick up his fitness, but it is not like if you have full pre-season training, and also he needed to settle down.
"But I think it is quite good for him that he can play some games this season before having a rest and he will learn from it.
"Tomas has settled in England, and settled in the team and he knows what we want from him.
"They are both very happy here and settling in well, and as far as the language is concerned, it is normal that they can understand more than they can say because it is always easier - but they are learning slowly."