Matthias Jaissle suffered defeat in his first home friendly as Newcastle United head coach as Bayer Leverkusen claimed a 2-1 victory at St James' Park.
Despite the result, Jaissle found positives in his young squad, particularly 17-year-old Mason Miley, who played until cramp forced him off on his first senior start.
Jaissle praised the teenager's determination after the match, highlighting the kind of commitment he wants from his players during a season of significant transition.
Newcastle are continuing to strengthen their squad and are making progress in their pursuit of Benfica right-back Amar Dedic.
Dan Burn, Tino Livramento, Bazoumana Toure and William Osula were also absent against Leverkusen.
However, following another pre-season defeat against Everton in midweek, Jaissle acknowledged that further reinforcements are required before the transfer window closes on 1 September.
The summer has already brought considerable change to St James' Park.
When Newcastle last played at home in May, Eddie Howe was still in charge and Nick Pope, Kieran Trippier, Bruno Guimaraes, Sandro Tonali and Anthony Gordon were among the players involved.
Since then, Guimaraes, Tonali and Gordon have been sold, while Newcastle have recruited four outfield players aged 20 or younger.
Goalkeeper Lukas Hornicek, at 24, is the oldest of their summer additions.
Burn, appointed captain by Jaissle, has admitted the scale of the changes made returning to the club feel almost like a fresh start.
Newcastle made the worst possible start against Leverkusen, falling behind after just 44 seconds.
Ibrahim Maza curled a superb effort from outside the penalty area beyond Hornicek, leaving Jaissle visibly frustrated on the touchline.
There was an unusual interruption midway through the first half when Newcastle changed kits because their traditional black-and-white strip with blue trim was deemed too similar to Leverkusen's mint and blue away colours.
After switching to their lilac third kit, Newcastle began to improve.
Anthony Elanga provided the equaliser with an inswinging corner that found Malick Thiaw at the back post.
The defender climbed highest and powered his header beyond goalkeeper Mark Flekken.
Newcastle struggled to create clear opportunities after that, though, and Leverkusen regained the lead in the second half.
Victor Boniface escaped Sean Steur inside the penalty area before driving a composed finish into the bottom corner to secure the victory for the German side.
Jaissle insisted he was not worried by the defeat as Newcastle prepare for their final friendly against Strasbourg on Sunday.
Attention will then turn to their Premier League opener against Liverpool at St James' Park, with Jaissle calling for supporters and players to remain united during the club's rebuilding period.
The Newcastle boss believes the atmosphere generated by the home crowd will be crucial as his youthful squad adapts to a new era on Tyneside.
