Sunday's 4-1 drubbing at Genoa left Napoli with three points from their first three Serie A games, an unimpressive tally for a club that spent big in the transfer market to reinforce a squad already rich with talented players.
The former Italy coach was called on to replace Edy Reja in March to halt the side's descent down the table after a strong start but his arrival did not lead to a late-season flourish.
The disappointing beginning to this campaign has shortened the odds of him being Serie A's second coaching casualty after Luciano Spalletti quit AS Roma, although the former Italy and AC Milan midfielder is not feeling the heat.
"I don't feel my position is in question. It would be absurd after just three games," he told reporters. "Instead I feel like a lion that wants to come back in a hurry."
Napoli's biggest close-season signing, Italy forward Fabio Quagliarella, demonstrated his ability with a brace in their 3-1 win over Livorno before the international break and he should be fired up for the clash with his former club this weekend.
However, Donadoni's quest to fix the defensive frailties exposed by Genoa have been complicated by a thigh injury that is expected to keep Argentine Hugo Campagnaro out for three or four weeks.
"If there are still problems in six or seven matches' time, then a deeper analysis of the situation will be needed," Donadoni said.
Udinese travel to Naples with four points after Serie A top scorer Antonio Di Natale scored a hat-trick in Sunday's 4-2 win over Catania to take his goal tally to six.
Genoa's city rivals Sampdoria, who have a made perfect start too, entertain Siena and champions Inter, who are two points behind the leading trio, visit Cagliari.
After gaining their first points by beating Siena in new coach Claudio Ranieri's first game last weekend, AS Roma
