By Paul Brown in Philadelphia

Paul Lambert believes the encounter against Philadelphia Union will be as severe as the sweltering USA heat.

Lambert, who took training this morning in 90 degree-plus temperatures, is expecting a "really tough" encounter against Union, insisting that the MLS "should not be underestimated."

Lambert's Villa take on Union on Wednesday 7.30am US/Thursday 12.30am UK and the new boss is relishing the contest.

The 42-year-old believes Villa will come up against a team from "an improving league."

He also thinks that the fact Union are well into their season and Villa haven't even begun theirs should provide an interesting fitness backdrop.

He said: "I don't think the league should be underestimated, I really don't.

"I know Scotland came over here a couple of months ago and were well beaten by USA national team. I don't think you can undersell it.

"There are some really good players in it and I think it's an improving league and we're in for a hard game, a really tough game.

"We are only one week into pre-season, we have had one game, there's still long way to go but we are improving. The fitness levels are getting better.

"Playing a game tomorrow night is going to be really tough for us but we will do everything can to make it as competitive as we can.

"But we also know that Philadelphia have played a lot of games this season. It's something we are looking forward to.

"Also, as their manager John said, the younger ones will have something to prove and that makes it harder for us too.

"Them being into their season definitely makes it more difficult for us but I am sure once the lads are here and there's a bit of an atmosphere in the game, things like that you'll forget.

"Some of them will play 45 minutes and yes, this is a big test for us.

"I am not sure what sort of crowd we will face, I am not sure how many people will be here tomorrow.

"But for our own selves it's important. If we do get a following from England we have to try and win the game.

"Even though it's a friendly you want to win it and get into that habit of winning. It's not be all and end all but it gives you a good habit for winning."

Lambert has been impressed with the attitude and application of his players as they impressed his coaching staff in the Philadelphia sunshine.

He added: "I think it's really tough. It's really strong. I felt it myself and I'm just standing watching it. The lads are under immense pressure with the heat. It's unforgiving.

"It's really severe. It's hard for us coming from a climate where we are not used to this sort of temperature.

"The lads will lose a lot of fluid as everybody knows - for some of them they might lose some weight.

"For us it's for training, we know how hard it's going to be. But for us it's a fitness thing because we have to get the lads up to speed.

"The attitude and the way they train, I have no problems."

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