The 20-year-old Kenyan goes into the meeting four points ahead of Morceli, the former world champion hurdler, Samuel Matete, and Britain's world triple jump record holder, Jonathan Edwards.
The American 100m champion, Dennis Mitchell, and the Olympic 400m hurdles champion Derrick Adkins are also in contention for the overall prize, worth up to $350,000 to the eventual winner.
The prize money consists of $200,000 for winning the overall title, $50,000 for winning an individual event and $100,000 for setting a world record. Komen is in such blistering form at present that he could even set a second world record inside a week.
At the Zurich Grand Prix on 14 August, he just missed out on breaking Haile Gebreselassie's 5,000m world record of 12:44.39 when he clocked 12:45.09, the second fastest time in history. Last Sunday in Rieti he destroyed Morceli's 3,000m record and, if he sets another world record today, in the 5,000m he would gain 45 Grand Prix points and ensure first place.
Morceli, though, has also been in good form recently and could secure the overall title he last won in 1994 with a world-record victory in the 1,500 metres.
The top four in the chase for the women's title are the American sprinter Gwen Torrence and the Swedish Olympic 100 metres hurdles champion Ludmilla Engquist, both on 66 points, together with the Jamaican sprinters Michelle Freeman (64 points) and Merlene Ottey (63 points). Ottey was the overall Grand Prix winner in 1987 and 1990.
Russia's Svetlana Masterkova, who won the 800m and 1500m double in this summer's Atlanta Olympics, set world records over 1,000m and the mile in Brussels and Zurich last month. Although she is out of contention for the overall prize, she can hope to end her season with victory in the 1500m.
Twelve world records have been set at the historic Arena stadium, which is now restored after years of neglect. The last was Ed Moses's 400m hurdles, when he achieved 47.13 seconds in 1980.
Rob Denmark, the Commonwealth 5,000m champion, has been granted a late entry in the Great North Run on 15 September.
Denmark is hoping to put the disappointment of missing the Olympic Games behind him by coming up with a strong performance on Tyneside.
"I was gutted," said Denmark, who was ruled out ofAtlanta with an Achilles tendon injury. "I vowed not to watch the Games on television, but naturally I did. It just rubbed even more salt into my wounds."