"Iran is better than Saudi Arabia in terms of technical points and players and will defeat its opponent with the support of 100,000 Iranian fans in Tehran," Daei said after a training session on Wednesday evening.
"The Iranian outfit has recently had a good training camp in Kuwait and the friendly match against the host helped Iran fully prepare for the Saudi Arabia match," he added.
The 40-year-old coach indicated that he did not yet know much about the new Saudi Arabia's Portuguese boss, Jose Peseiro, but that Iran could defeat its opponent with any technical staff.
Saudi Arabia is slated to arrive in the Iranian capital on Thursday evening to face Iran at 19:00 local time (14:30 GMT) on Saturday.
The two teams drew 1-1 in the first leg of the final round of qualification matches for the 2010 World Cup. The game was played in the Saudi capital of Riyadh.
The Iranian squad is in Group B of the 2010 World Cup qualifiers along with Saudi Arabia, South Korea, the UAE and North Korea.
South Korea now tops the chart with eight points, while North Korea is second on seven. Iran is in third place, with six. The UAE is now ranked at the bottom with just one point.
The top two teams in each group qualify for the World Cup finals. Third-place teams face-off in a two-leg play-off with the winner taking on Oceania zone victor New Zealand for a place in the finals.