Northern Ireland manager Nigel Worthington hopes his team raise their game next month when they face Slovenia in the opening Euro 2012 qualifier in Maribor.
He also wants a different attitude from certain players following the 2-0 defeat by Montenegro in a warm-up match in high humidity.
Radomir Dalovic, who has been linked with a move to Wigan and Hearts from Croatian club Rijeka, scored both goals, either side of half-time.
It means Northern Ireland have gone 10 games without a win and failed to score in seven of them.
Worthington said: “We didn't perform as well as we wanted, we didn't get the result we wanted. They were much brighter and sharper than us.
“Our players looked as though they were at the start of the season.
“I am hoping they will have four or five games under their belt when we come together again and do what is required to get a good result (against Slovenia).
“Yes, it was warm but I am not looking for excuses. It was warm for them as well.
“It will probably be warm in Slovenia in three weeks so in circumstances and situations like that you have to deal with it.”
Worthington is aware both Martin Paterson and Kyle Lafferty could have been sent off had it been a competitive game.
Paterson incensed Montenegro by flooring Milorad Pekovic while Lafferty railed at Serbian referee Bosko Jovanetic.
Worthington said: “You know what I am like regarding discipline. You cannot raise your hands. In a qualifier there is a good chance of (Paterson) being sent off.
“Kyle approached the referee after being booked and ran the risk of another yellow. We need to give the referee the respect he deserves regardless of decisions and get on with the game.
“If you lose a player in a qualifier it can be very costly. But overall our discipline has been good.”
Northern Ireland found it hard going but Worthington remained calm in the dressing room after the defeat.
“There was good conversation between us,” he said.
“We all agreed what was discussed and that the tempo of our game was slow, the pressing wasn't good enough and the passing should have been better.
“In the first 10 minutes of the second half we were better. The kids did superbly well. They joined in, they kept the ball moving. It was our best little period.
“But we have gone to sleep, switched off and it’s another goal for them.
“It doesn't come simpler than that. Let's learn from it.”