The Russian side looked dangerous on the counter-attack in the first half but eventually lost the game to Son Heung min's 71st-minute strike.
"We knew Spurs would have a lot of possession, would dominate us in that part of the game," Slutsky said.
"The goal was marginally offside, maybe yes, maybe no, we have to see it again, but it doesn't matter.
"In second half we tried to attack more but we didn't take our chances and that's why we are here."
CSKA now sit bottom of the Group E table with one point, after their 2-2 draw at Bayer Leverkusen a fortnight ago, while Spurs are second on three points in the wake of their home defeat to Monaco and win over Moscow.