Coming off a 3–1 victory over Uganda in their opening match, the Carthage Eagles were undone by goals from Victor Osimhen, Wilfred Ndidi and Ademola Lookman.
Despite strikes from Montassar Omar Talbi and Ali El Abdi, the North Africans were unable to avoid defeat against Eric Chelle’s Super Eagles, marking only their second loss in their last 12 AFCON matches.
While Trabelsi acknowledged the disappointment of the result, he insisted the performance showed Tunisia are capable of competing at the highest level.
"Of course, there is a sense of bitterness after the match and the defeat. We felt we could have come back, especially during the final 30 minutes," the Tunisian legend told the CAF website.
"The players performed at a very high level in that period; we created many chances, scored two goals and could have scored more.
"The defeat hurts, but there is also a positive aspect: it shows that we can compete with any opponent when we impose our style of play and our ball possession.
"We respected them, yes, while trying to remain balanced. We know that Nigeria have very fast and powerful players, so we tried to reduce the spaces."
Trabelsi explained that his side adopted a balanced approach in response to the Super Eagles’ quality, but pointed to missed chances and a failure to win key duels as the factors that ultimately proved decisive.
"In the first half, we had a few chances that we should have taken," he continued.
"The goals we conceded came from crosses; it was not a matter of too much respect, but rather that we lost too many defensive and attacking duels.
"Once we started winning our attacking duels, we were much better and put the opponent under pressure.
"I repeat, we did not start the match well because we lost too many duels. However, over the final 35 minutes, we were dominant and the final result could have been very different.
"It is a matter of judgement. When we needed even more attacking penetration, we introduced Ismail Gharbi, but the performance of those already on the pitch was not poor. The next match will be decisive."
Following the defeat, the 2004 African champions sit second in Group C with three points from two matches.
They will face Tanzania next on Tuesday at the Rabat Olympic Stadium, knowing that a win is crucial to secure a place in the Round of 16.
