"But it is true that most of us think he would serve our cause better if he were in Egypt more often," Yussef told AFP.
"We still believe that boycotting the elections was the right choice for the opposition.
"Everything going on at the moment demonstrates that participation is absurd," given the certain victory of the ruling National Democratic Party, he added.
The Nobel Laureate and former head of the Vienna-based International Atomic Energy Agency appealed to Egyptians in September to shun the vote -- a call heeded only by a few small parties and rejected by those in the outgoing parliament.
The Muslim Brotherhood, Egypt's largest opposition force, as well as the liberal Wafd opposition party both decided to field candidates.
Brotherhood candidates stand as independents, to bypass a ban on religious parties.
"Our decision to participate in the elections... is due to the fact that it is the only peaceful path to change," the Islamist group's leader Mohammed Badie said this week.
"The elections are a window that allow us to live alongside the people and promote the call for reform," he told the Arab satellite network Al-Jazeera.
ElBaradei's absence sharply contrasts with the enthusiastic welcome he received at Cairo airport on his return to Egypt in February after 20 years abroad.
His demands for constitutional reforms, which would allow independents such as himself to stand as candidates in next year's presidential election, were quickly dismissed by the government.
Amr Hamzawi, an Egypt expert at the Carnegie Endowment for International Peace, believes that the long periods ElBaradei has spent out of the country have damaged his political prospects.
"The biggest mistake he made was that he didn't stay in Egypt," Hamzawi told AFP. "He says he wants change, but he spends three-quarters of his time abroad, which casts doubt on his personal commitment."
It is a view that is also shared by some diplomats.
"He is a man of integrity and experience but the degree of his (political) commitment has never been resolved," said one Western diplomat in Cairo.
But some ElBaradei supporters says his cause is bigger than one man.
"Of course his absence has provoked dissatisfaction. But let's try to understand. He insists that change cannot be tied to one person alone. He wants it to be tied to the people themselves and to their wishes." Haytham Abul Ezz Hariri told AFP.
In the polling booths on Sunday it will be difficult to gauge the effect on the Egyptian electorate of ElBaradei's call for a boycott, given the traditionally low turnout.
Official figures put the level of participation in the 2005 parliamentary election at just 26 percent, and 23 percent for the last presidential election.
"Given the low level of participation in the previous elections, I don't think the boycott is going to have much of an impact," said Emad Gad of the Al-Ahram Centre for Political and Strategic Studies.