The manager felt his team had moments of control but ultimately failed to capitalize on their chances.
He stressed the need for a more clinical approach as they look to bounce back in their next fixture.
He told the BBC: "The difference between the first and second half (was big). The whole first half we were going back instead of putting our opponents under pressure.
"We don't have too many results. Also in bottom three. We were too passive and too secure in our defensive organisation. We didn't press the opponent at all. The backline was too deep, the midfield too.
"The second half you have a totally different game but you've conceded two.
"Nothing at all (changed tactically at half-time). The intensity of the players. Forwards pressing. The higher back line and midfielders following on the pressure of the forwards.
"That is the way forward literally.
"When you are passive and hope the opponent doesn't score, you call it upon yourself. The easy goals we conceded are a part of it."