World champion Ato Boldon and Olympic champion Michael Johnson will race each other over 200 metres for the first time this year when the Golden League comes to Rome tomorrow.

The prospect means that the half-lap race looks set to overshadow the 100 metres sprint, where world record holder Maurice Greene is overwhelming favourite to win.

"Yes I'm going to run the 200," Boldon told reporters this week. "With Michael Johnson there I've got my work cut out for me. I've already teased Maurice that he's got the easiest job of the two of us here."

The Trinidadian, who equalled his personal best of 9.86 seconds to beat Greene over 100 metres at a Grand Prix meeting in Lausanne on Friday, is still suffering minor tendonitis and a back injury caused by a fall in Helsinki.

He holds the fastest time this year in the event and will start favourite against world record holder Johnson, who will be running his first 200 metres for six weeks.

"My focus is the 400 metres and whatever happens in the 200 metres happens," Johnson said.

Greene's main challengers in the 100 metres race will be Canadian Bruny Surin, Britain's Dwain Chambers and 1992 Olympic bronze medallist Dennis Mitchell. Only Surin, with 9.92 seconds, has run a time this year which will trouble Greene, whose 9.79 shattered the world record in Athens last month.

World champion Marion Jones is clear favourite to win the women's 200 metres and continue her assault on a slice of the £1.0 million jackpot which the IAAF shares between athletes who win selected events at all seven Golden League meets.

Morroco's Hicham El Guerrouj returns to the track where he produced an astonishing run a year ago to slash more than a second off the 1,500 metres world record.

Denmark's Wilson Kipketer starts as favourite in the 800 metres while double Olympic champion Svetlana Masterkova is expected to dominate the women's event.