Forest won 2-1 as Arnaud Kalimuendo's opener was canceled out by Mike van der Hoorn before Igor Jesus struck an 88th minute winner.
Jans remarked afterwards: “After 15 minutes, I thought 'this is going to be a very long night'. They had two or three really good chances.
"But then we got back in the game. In the second half, they brought in more established players and took the lead, but then suddenly it was 1-1. It's a shame we lost, because we gave two goals away through defensive mistakes.
“We showed more courage on the ball than in other matches. But in the first 15 minutes we pressed and went one-to-one, and the play was too spread out and their No24, (James) McAtee, was always free.
"It would have obviously been great to take a point, but let’s be honest: that probably wouldn’t have been enough to help us go through anyway.”