Alex McLeish began his second tenure as Scotland boss with an uninspiring 1-0 defeat by Costa Rica at Hampden Park.
An experimental home side who started with four debutants fell behind in the 14th minute when Marco Urena scored what proved to be the winner with a well-taken finish.
The expected raft of substitutions after the break led to a more disjointed game with Scotland huffing and puffing until the end.
The only previous meeting between the two countries was at the Italia 90 World Cup when Costa Rica won 1-0 in what was their first ever World Cup match.
This result was less of a surprise -- Los Ticos are on their way to Russia in the summer for their fifth World Cup appearance.
McLeish will no doubt tinker again for the friendly away to Hungary on Tuesday night and there are further challenge matches in Peru and Mexico at the end of the season.
By that time, the former Aberdeen and Scotland defender will have a better idea of what he has available for the inaugural Nations League which begins later in the year.
At Hampden, McLeish was shown that he has a lot of work to do.
Aberdeen defender Scott McKenna, Manchester United midfielder Scott McTominay -- watched by club boss Jose Mourinho -- Fulham playmaker Kevin McDonald and Swansea striker Oli McBurnie, on loan at Barnsley, were the new faces in from the start.
Costa Rica boss Oscar Ramirez, who played against Scotland in Genoa, kept his promise to start with a strong team.
Real Madrid goalkeeper Kaylor Navas was the biggest name with Celtic defender Cristian Gamboa, a bit-part player at Parkhead, playing wing-back.
Amid an almost eerie atmosphere the Central American side looked neat and tidy and their opener was simple, Sunderland's Bryan Oviedo getting free down the left and cutting it back for Los Angeles FC's Urena to side-foot past keeper Allan McGregor with some assurance.
The Scotland fans groaned then gasped three minutes later when wing-back Callum Paterson headed a Matt Ritchie corner past the far post.
McBurnie looked the most likely Scot. His drive in the 27th from the edge of the penalty area was parried clear by Navas and before the break he had a shot from inside the box blocked by Costa Rica defender Oscar Duarte.
Scotland started the second half with some energy but in a swift break Costa Rica captain Bryan Ruiz left Andrew Robertson for dead and clipped the bar with a left-footed shot.
There was no lack of effort from those in dark blue.
In the 65th minute Navas palmed a powerful Ritchie drive on to the roof of the net for a corner, which McBurnie headed over before he just failed to get on the end of a Robertson cross.
Attacker Jamie Murphy, on loan at Rangers from Brighton, made his debut as a replacement for Ritchie with four minutes remaining before Robertson headed a Paterson cross wide of the target and the home side hustled and bustled some more but to no avail.