Seydou Keita have Barca the lead on 72 minutes, but an own goal by Gerard Pique made it a draw.
Guardiola told Marca: “It feels uncomfortable not to win when you have been so close.
“We knew that they would press us, but we controlled their play. We have lost two points, but I am happy with our performance.
“Sometimes chances are taken, and sometimes they are not. A lot of circumstances led to the own goal, but their only other threat in the second half was from a Nekounam free-kick.
“Last week Osasuna conceded in the last minute, and this week they equalized. This is football.
“We must now recover and get a good result in Russia.”