THE old saying goes that familiarity breeds contempt, but that certainly doesn't ring true for Essex colleagues and housemates Alastair Cook and Mark Pettini.

The England opener and county captain share a house in the village of East Hanningfield, and their strong friendship has inspired both to great things on the cricket pitch.

While Cook, 23, has become an England regular, Pettini has risen to skipper Essex at the age of just 24, making him the youngest captain in county cricket.

And the pair will hope the success continues when they take to the field in Essex's LV County Championship Division Two clash with Derbyshire at Derby this morning.

Last time Cook and Pettini played championship cricket in the same team, in May 2007, the old friends shared an opening stand of 190 against Northants, only for Essex to go on and lose the match by six wickets.

This time around, having already thrashed Northants by a convincing nine wickets - and Kent by 31 runs in their Friends Provident Trophy opener - the two will be hoping their combined efforts help Essex continue their unbeaten start to the season.

That start has included a welcome return to batting form for Pettini, who dropped down to number five in the batting order after a poor 2007 and has responded with 80 not out against Northants and 119 in Sunday's win at Canterbury.

And more than anybody else Cook, who replaces Varun Chopra, has been delighted for his best mate.

"Mark's got the character to come through what happened to him last year. It will only have helped him to have started the season as a player and then suddenly becoming captain and losing three of your best players," said Cook, who makes his first Essex appearance of the season today, having scored four centuries in his last 10 county championship innings "It would have been hugely disruptive and he'll have learned a lot from how hard that was.

"I know he's been working hard on his batting and getting the balance right."

Pettini, meanwhile, has been impressed by both his own accomplishments and those of his team-mates.

And the former Cardiff University student is keen to see his team's fine start to 2008 continue at The County Ground, but he knows it will not be easy.

"Derby have got a different look about their side this year. They've made a big effort to revamp their side there and it's going to be a tough game," he observed.

"We're not sure exactly what to expect out of their wicket, but we'll take a squad to cover all eventualities.

"We're on a bit of a roll and go into the game full of confidence so we'll see how we go."

Essex (from): Pettini (capt), Cook, Gallian, Westley, Bopara, ten Doeschate, Foster (wkt), Middlebrook, Tudor, Wright, Nel, Masters.