The Tartan Army boss and his squad arrived in Belgrade still unable to fathom out their woeful start to Friday night's 2-1 defeat to Wales at Hampden Park - a result which kept them rooted to the bottom of Group A with two points from five games.
"It was a freak 25 minutes," said Strachan at the pre-match press conference at the Scotland hotel. "I can't call it a bad 25 minutes. I thought it was freaky, what I (saw) was totally unusual. I spoke to the players and they had never seen anything like that 25 minutes anywhere in their footballing career. I don't think that will ever happen again - I know it won't happen again."
He added: "So I put that aside and look at the next 20 minutes which was fine, we got into a rhythm.
"The second half was fine, we looked like we were going to score and then we lose a goal and then the last 15 minutes, we didn't really count that
"It was a disappointment for everybody who went there on Friday night, people were scratching their heads as to what happened for the first 25 minutes, but as I say, it was a freak 25 minutes."
Already without Darren Fletcher, Scott Brown, Ross McCormack, Danny Fox, James Forrest and James Morrison, Strachan's squad was weakened further when defender Russell Martin withdrew with what is believed to be hamstring injury and midfielder Kris Commons stayed behind for personal reasons.
Moreover, Robert Snodgrass is suspended for picking up two yellow cards against Wales.
Birmingham City defender Paul Caddis has joined up with the squad whom the former Southampton, Celtic and Middlesbrough boss believes are still licking their wounds following the defeat to Wales.
"We are still in the process of making ourselves feel better and we will do that by training and putting together a plan," he said. "We are all hurting that's for sure. The players realised that it was an opportunity wasted and I realised that as well. It is hard and the only way you can get rid of your frustrations is by playing and winning games of football."