Spurs drew 2-2 with Gent at Wembley to miss out on the Round of 16 by losing 2-3 on aggregate to the Belgians.
After going into the second leg a goal down, Spurs conceded an unfortunate own-goal before Dele Alli was sent off late in the first half, reducing them to 10 men.
The home side dominated the second half but were unable to find the goals to send them through, prompting this reaction from the boss.
"Very disappointed," he told BT Sport.
"It was game we were excited to play today in front of our fans. We started the game very well and scored and the tie was open, but we concede a goal in one action, an own goal.
"Then it was more complicated with the send-off.
"But I feel very proud. We played well in the second half, we scored the second goal, we then needed more to go to the next round but we conceded.
"But we played very well and I'm proud."