The Portuguese manager has been credited for masterminding a 2-0 win over Liverpool at the weekend with a defensive approach.
However, Souness has claimed that employing such tactics is "the simplest way to play".
"I laugh when I hear people talk about "tactical genius" because that's absolute tosh. I agree with [Liverpool boss] Brendan Rodgers when he says that the tactics Mourinho has employed in the last two matches are the simplest way to play," he told Sky Sports News.
"It's not hard to set up a back four that doesn't go anywhere and a midfield in front of them not going anywhere and look to catch your opponents on the break or from a set-piece - but where Mourinho deserves all the credit in the world is the fact that he has top, top players buying into that approach."
Chelsea welcome Atletico Madrid in the second leg of their Champions League semi-final on Wednesday evening.