The young Honda rider's death at the Malaysian Grand Prix has cast a pall of gloom over the sport as the curtain falls on the campaign.

Under normal circumstances - and with the MotoGP world title already won by Australia's Casey Stoner - another Italian, Loris Capirossi, could have hoped to have been the focus of attention as he will retire after the race following 22 years of world championship action.

Former 250cc world champion Capirossi will make his 328th and final Grand Prix start and the Pramac Racing rider says he and his fellow racers are determined to pay a fitting tribute to Simoncelli.

"It will be difficult to be in the paddock without Marco, as everyone will miss him. No one will feel like going on the track, but we have to do it for him and for all fans of motorcycle racing," Capirossi said.

Teammate Randy de Puniet said, "It will be really difficult to race at Valencia without Marco, but part of our job is to continue."

Despite the deep mourning the sport is in following the Simoncelli tragedy, the Italian's Gresini Honda manager Fausto Gresini, says the show must go on - and that Simoncelli would not have wanted it any other way.

"The decision was not easy but we made a choice as we think that's what Marco would have wanted," Gresini said.

"Putting our wheels down on this track is the best homage we could pay to him."

Participants will make a special, poignant tribute at the Ricardo Tormo circuit on Sunday morning just after the warm-up session.

Honda's Stoner agrees with Gresini that the race absolutely must go ahead.

"It will be difficult to resume competing this weekend but that's without doubt the best way to honour his memory," Stoner said.

Yamaha Tech 3 rider Colin Edwards, who along with Valentino Rossi saw Simoncelli veer right into their path at Sepang, dislocated his shoulder in the accident and on Sunday will give way to double Superbike champion and fellow American Josh Hayes.

Spaniard Jorge Lorenzo, who will finish as runner-up, will miss the race, which he won last year, as he recovers from finger surgery after crashing at Phillip Island.

Replacing Lorenzo will be Yamaha test rider and All Japan Superbike competitor Katsuyuki Nakasuga, making his second appearance in the MotoGP premier class on behalf of Lorenzo.