Liam Ridgewell will be walking a disciplinary tightrope this weekend when Birmingham City take on Everton at Goodison Park.

The in-form centre-back has been booked four times so far this season and he heads to Merseyside on Saturday knowing a fifth would put him out of the Second City derby on Sunday week.

The prospect of missing such a crucial match would weigh heavy on anyone's mind but the match with Aston Villa carries extra significance for Ridgewell following his transfer of allegiance in the summer.

The 23-year-old made 93 appearances in the Claret and Blue over a five-year spell that saw him arrive as a young prospect from Bourne-mouth and grow into a first-team regular.

In the 2005-06 campaign, he started 30 Premiership games and scored five goals in what turned out to be David O'Leary's final season as manager.

But last term, following the arrival of Martin O'Neill and the return to fitness of Martin Laursen, the Londoner found opportunities increasingly hard to come by and from January onwards he failed to make the first team.

That prompted a move to Villa's bitter rivals and he will face the Ulsterman and his former team-mates with something of a point to prove - assuming he manages to stay out of Mike Riley's notebook on Saturday.

According to Birmingham goal-keeper Maik Taylor, it's something that is already playing on his mind.

"He has said that he is on four bookings so he is praying he won't get booked next week and miss the big one," said Taylor. "Any suggestion that he might go easy? I'll be scrutinising his performance."

It is unlikely. Along with Olivier Kapo and Stephen Kelly, Ridgewell is one of just three players who have started every league game for Birmingham so far and in the process he has convinced any sceptical supporters who resented his former allegiance just how dedicated he is to the new cause.

The promise of regular selection has proved a powerful motivator.

"He really wanted to play more regularly," Taylor said. "He wasn't given too many opportunities [at Villa] but he has come in and done well for us.

"That doesn't mean he is complacent. He has to produce and up to now he has been great for us. Possibly he has had to produce a bit more because of coming from Villa.

"He was on trial with the fans. There was pressure from that but he has come in and you can see he is enjoying himself and he is playing very well."

So well in fact that any slips made for Wigan Athletic's first goal in last weekend's 3-2 victory were erased by his first goal for Steve Bruce's men with a promise of more to come.

One at Goodison Park on Saturday would go a long way to consolidating the vital three points Birmingham took in their last outing and maintaining the current average of a point a game - which should just about keep them in the top flight.

So far City have specialised in beating the teams around them. Before Wigan, Bolton Wanderers and Derby County have fallen victim to Bruce's revamped side but Taylor knows they will have to take some bigger scalps too if they are to remain in the division.

"There are no easy games and every week is a battle and a fight. We've been playing some good stuff but first and foremost we need to mix it with good teams because we know we are going to be in for a fight every week," he said.

"The results against these teams have gone for us but it would be nice on the back of good performances against teams at the top to be able to have something to show from those games just to help the belief in the camp.

"The Premier League is very new to a lot of the lads here. It is a young squad but they are all enthusiastic and have that will and hunger and desire to get results.