The adviser acknowledged that Biden's performance in Atlanta was "lackluster" but said the campaign is committed to highlighting the moments it believes worked for their candidate and then moving on, the report said.
The adviser recalled that former President Barack Obama was also dissatisfied with his own performance during the first debate, but he still won reelection.
Following Thursday's debate, 67% of registered voters who watched it said that Trump performed better, while only 33% of those polled said Biden won the debate, according to a CNN poll.
Prior to the debate, 55% of voters favored Trump, and 45% expected Biden to put up a better performance, the broadcaster reported.