Graeme Le Saux told Goals on Sunday that David Luiz should have been sent off for his reckless challenge on Jonathan Walters.
The Chelsea defender was criticised by Stoke manager Tony Pulis for a "dreadful" high tackle on the Potters forward, which he felt merited a straight red card. However, referee Michael Oliver opted to punish the Brazilian with a booking.
Le Saux had two spells at Chelsea and currently works as an ambassador for the club, but says he can't excuse Luiz's actions and says he should have been dismissed for the foul.
He told Goals on Sunday: "What I don't understand is that it's on the half-way line and he suddenly decided he's going to go and get something; it doesn't seem like he's too bothered whether it's the ball or the player.
"He shot forwards and was never getting the ball, which means he lunged for the player. Seeing it, even in real time, it's a red card.
"He was nowhere near the ball and Walters was fortunate to get away without getting quite a nasty injury there.
"He got a yellow card and the irony is that's his punishment now. That can't be retrospectively turned over.
"He got a yellow card and got away with it, but I'm sure the referee will look at it and think he's got it wrong."
Chelsea's 1-0 win over Stoke has left them sitting top of the Premier League, unbeaten after five games.
The Blues won the Champions League and the FA Cup last season, but limped to a sixth-place finish in the Premier League and Le Saux says they are in a strong position to improve on that during this campaign.
"Last year was incredible; disappointing in the league but winning the Champions League and the FA Cup," he said.
"In the league this year they've got fantastic momentum to start off with and they've got a great chance because they've got so many creative players.
"I wouldn't be surprised in January if they don't go back into the market for another striker to back up Torres. They've got Daniel Sturridge who wants to play up front and Eden Hazard can play up there as well. They're a very creative side and if Chelsea buy somebody they'll go for a world-class striker.
"Oscar's had a fantastic couple of weeks; he's playing very well. With the creativity of Juan Mata, Oscar and Hazard on the pitch you've got good options.
"They should be scoring goals."