Steve Clarke revealed his surprise and disappointment after hearing some boos from the Tartan Army following Scotland's 1-0 defeat by Japan at Hampden Park.
The Scots were cheered off the pitch in November after a dramatic 4-2 win over Denmark qualified them for the World Cup finals for the first time since 1998.
However, their return to the national stadium for the first of their warm-up games for North America was more sedate.
Both sides hit the woodwork in the first half, but Hajime Moriyasu's visitors got the breakthrough in the 84th minute through substitute Junya Ito and the home fans revealed their frustration at the end.
Asked if he was surprised by the reaction of the fans, Clarke said: "Yes and it disappointed me to be honest.
"It's just the modern way, it seems to be now if you lose a game you get booed.
"You have just got to deal with it. It disappoints me."
Scotland take on Ivory Coast at Everton's Hill Dickinson Stadium on Tuesday night and they have two more warm-up games against Curacao and an as-yet-unnamed opponent before they take to the biggest stage of all for the first time in 28 years in the USA, where they face Haiti, Morocco and Brazil in their group.
If there was a sense of anti-climax about the game against Japan, the Tartan Army will no doubt see a more energised home side when it matters this summer.
Middlesbrough striker Tommy Conway was handed his first start, while skipper Andy Robertson was earning his 91st cap to go second-equal with former Aberdeen and Manchester United goalkeeper Jim Leighton.
Celtic's Daizen Maeda, Japan's captain, was the most familiar face to the home fans.
The visitors, on their way to their eighth successive World Cup finals, survived an early fright.
In the eighth minute Scott McTominay had a terrific chance to open the scoring when fellow midfielder John McGinn teed him up with a cross from the right but his unconvincing shot from 10 yards was pushed on to the post by Japan 'keeper Zion Suzuki and away to safety.
Moments later at the other end, Joel Fujita was given time and space to send in a powerful drive from 30 yards which tested Gunn, who then saved a long-distance effort from Kodai Sano just before the half-hour mark.
The home side defended a series of corners as Japan tightened their grip and in the 38th minute Sano clipped the top of the bar with a side-footed drive from inside the box. The match went back and forth.
Gunn thwarted Yuito Suzuki as Japan broke with purpose before a McTominay header was saved by Suzuki just before the break with the Napoli playmaker seeing his free-kick from 25 yards tipped over the bar by the Parma 'keeper early in the second half.
Suzuki then parried a drive from Robertson past the post as Scotland stepped up the pace.
Ryan Christie and George Hirst replaced McGinn and Lyndon Dykes just after the hour mark before one of Japan's many substitutes, Kaoru Mitoma came close with a shot from the edge of the box following a cleared corner, with Gunn denying Ito moments later.
The visitors' threat intensified and Scotland midfielder Kenny McLean cleared a dinked shot from Ito off the line in the 69th minute before Hirst hit the side-netting with a drive.
Findlay Curtis replaced Conway to make his debut in the 80th minute but four minutes later Genk midfielder Ito burst into the Scotland box to beat Gunn from 12 yards and end the stalemate.
Scotland head coach Steve Clarke:
"You've got to look at the quality opposition, we're playing a top-class team, and towards the end they're bringing on stronger and stronger players.
"I chose to go the opposite way because I had players that I needed minutes on the pitch, but I also had to protect towards the end of the game.
"It's just to keep working, it's to keep working at what we do.
"I didn't think it would be a low-scoring game, it was. Even the goal we conceded came from a bad choice to go forward too early, and we weren't organised after defending a set-play.
"We can learn little lessons, but I think it shows that if you make bad decisions against top teams, you get punished.
"It was disappointing to lose the game, I don't think it's a game that we should have lost, if I'm being honest.
"We'll go away, we'll analyse the video. One or two things that I thought were decent in the game, I thought we defended quite well, I thought the two centre-backs were good, I thought Angus was really good in goals."
