French international Ousmane Dembele is yet to settle in Barcelona since moving from Borussia Dortmund in an £135m deal over the summer.
The 20-year-old winger was an unused substitute during Tuesday night's 1-1 draw in the Champions League against Chelsea.
Antonio Conte's side took the lead through a brilliant Willian strike and Ernesto Valverde immediately responded by making a substitute.
Needing a goal, the Barcelona coach brought on Aleix Vidal instead of Dembele.
"It's not the moment for experiments or to do tests," said Valverde when quizzed on why he chose Vidal over Dembele. "That's how I see it.
"He spend a lot of time injured and for a game with this characteristics, the managers bet on the things they know and we have a seen it rather than an expectation."
Dembele, who has been sidelined for much of the season through injury, has made just eight appearances for Barcelona thus far.
It's important to remember that he's only 20 - and one of Dembele's teammates is acutely aware of his difficult situation.
The moment Messi stopped training to applaud Dembele
The Barcelona players returned to first team training on Thursday and an awesome moment was captured by the club's media team.
Dembele nutmegged Jordi Alba during a Rondo exercise and the ball was quickly passed onto Leo Messi.
The 30-year-old Argentine, obviously hoping to inspire confidence in his young teammate, paused the Rondo exercise to applaud Dembele.
Absolute class by Messi - it's almost reminiscent of how Ronaldinho treated Messi in his early days at the Camp Nou.
Barcelona fans loved it
Plenty of Barca supporters on social media were keen to heap praise on their all-time record goalscorer.
Football will not be the same without Messi.
Barcelona are seven points clear of Atletico Madrid at the top of La Liga and host Girona on Saturday evening.
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