Villa striker Darren Bent admitted it was "disappointing" to find out he had been axed only after arriving at the ground for last Sunday's derby clash with West Brom.
But Bent responded with the equaliser in a 1-1 draw as a second-half substitute and Lambert believes his methods keep players on their toes.
Lambert, whose side visit Tottenham on Sunday, said: "It's just something I've always done. If you tell someone they're going to play two days before the game, I think they might take their foot off the pedal a little bit.
"There's nothing better than sitting on a knife-edge at times and you have got to be ready for that game. That's just the way I have always done it."
Lambert insists his relationship with Bent is fine and he has not held talks with the former Tottenham player over his non-inclusion against the Baggies.
But he concedes he has a welcome selection problem with Gabriel Agbonlahor also in fine form after his recent brace against Manchester City.
Lambert said: "I've said 'good morning, how are you - I'm fine' - that's it.
"I don't have a problem with Darren, I don't need to raise it. I'm not giving him the silent treatment.
"I think that, with Gabby scoring two at Man City, what it does is it gives you a problem. But come Sunday, I'll do what I've done for years, try to pick a team that may win us the game. I don't have any problems with anybody.
"Whether you are on the field of play or you are coming off the bench, you have 10 other guys right behind you and a crowd willing you on.
"To be fair to Darren, he came on and it was an absolutely brilliant finish. He is a natural goalscorer.
"I don't have any problem. Some of the best players in the world have been left out. I need everybody as it is a really long, tough season."
Meanwhile, Lambert is unsurprised at Celtic keeper Fraser Forster's inclusion in the England squad for the forthcoming World Cup qualifiers with San Marino and Poland.
Lambert gave Forster his first elongated spell of senior action when on loan to Norwich from Newcastle during the 2009-2010 season.
He helped the Canaries gained promotion from League One with 18 clean sheets in 38 games and joins the current Norwich keeper, John Ruddy, in the England set-up.
Lambert said: "It's brilliant for the two of them. John's been in the squad before and Fraser I'm delighted for because he is a top keeper.
"No two ways about it, he is an absolutely top keeper. He made saves that I never thought were possible at certain times.
"We saw Fraser playing on loan to Stockport I think. He played against us. He's a big lump of a man.
"I think he was just about to re-sign for somebody when we kind of stepped in. In that League One he was fantastic."
Lambert has two in-form, experienced keepers of his own to choose from at present in Shay Given and Brad Guzan.
He said: "Brad is playing really well at the minute and I thought Shay was excellent against Manchester City in the Capital One Cup."