Alex McLeish said nerves were to blame for Scotland's uninspiring display in their 2-0 Euro 2020 qualifying win away to San Marino on Sunday.
Kenny McLean's early header got Scotland up and running as they sought to bounce back from Thursday's embarrassing 3-0 loss in Kazakhstan.
But McLeish's side, who earned promotion in the Nations League last year, struggled to break down FIFA's lowest ranked team at San Marino Stadium.
It took until the 74th minute until Johnny Russell ensured they would have three points to show for their efforts.
Scotland's dire display was met by boos from the travelling supporters and McLeish understood why fans were dissatisfied.
"They were frustrated we didn't kick on from the first goal," he said. "I have heard booing over the years during my career. That happens in football.
"Sometimes the players get nervous about that and that's why you don't get the free-flowing football you saw in November [in the Nations League]."
McLeish denied feeling the pressure as Scotland seek to qualify for their first major international tournament since 1998.
"I don't really think of it that way," he said. "I do believe it was obviously very important that we won the game.
"We dealt with it. We did want more goals of course and that makes everybody a wee bit happier.
"I think all the Scotland results and performances here before were just 2-0. In the end, we should have had four or five.
"We got a whirlwind start against us from the Kazakhs and it really set us back in that whole game and I think it left a few of us shell-shocked.
"We dealt with the second game, if not fantastically, but it was professional enough."