Colin Jackson has decided to step back on to the track to help two of Britain's leading athletes in their quest for medals at the 2008 Olympics.
Benjamin and Williams will be coached by Jackson in Cardiff
Jackson will coach Tim Benjamin and Rhys Williams, who are returning home to Wales after being based in England.
Benjamin and Williams won silver for Britain in the 4x400m relay at August's European Championships in Gothenburg.
"In Tim and Rhys I've found athletes who really want to make something of themselves," said Jackson.
"They also have the ability to do so. We all know they can win medals, but they need to be more consistent in their top level performances.
"I will work with the two of them initially up to Beijing (host city for the 2008 Olympic Games) and then see how things have been going.
"If we are successful, then hopefully we can continue on to the London Olympics in 2012."
I feel ready to put something back into the sport
The decision means Benjamin will no longer work with coach Tony Lester while Williams leaves Nick Dakin's Loughborough base.
Benjamin announced himself on the world stage last year when he broke 45 seconds for the first time in beating 400m Olympic champion Jeremy Wariner in London.
He finished fifth at the World Championships two months later, and ended the year with a personal best to take second at World Athletics final in Monaco and finish fourth in the world rankings.
Injury forced him to miss this year's Commonwealth Games, and the after-effects of the groin injury were evident at this summer's European Championships as he battled to a sixth-place finish.
Williams is a 400m hurdles specialist who has progressed from being European Under-20 and Under-23 champion to making the 2005 World Championships semi-finals.
The 22-year-old then provided some much-needed cheer for British athletics at the European Championships in August when a fantastic late surge secured a bronze medal.
In his role as a BBC commentator, Jackson identified the flaws in Williams' hurdling technique and now the former 110m hurdles World champion and record holder is eager to share his expertise.
Jackson, who ended his illustrious career in 2003, said: "I feel ready to put something back into the sport.
"What I have missed most is the ability to work with high-skilled and high-performing athletes.
"I'm afraid I'm not really interested in starting off someone's career and trying to turn a nobody into a someone.
"All my expertise, and all my recent knowledge, lies at the top end of the sport."