The 18-year-old came on with 16 minutes to play on Tuesday and netted his first senior goal four minutes later as Barca romped to a comprehensive 8-1 win on the night and 12-1 success on aggregate.
Traore made an immediate impact with a mazy run that saw him skip past several challenges before applying a neat finish beyond Dani Jimenez.
The young forward now hopes to keep impressing Barca's head coach.
"I am happy for the opportunity Luis Enrique and the coaches gave me," he said. "It's a great feeling to play with the first team.
"It's exciting for any youth player to debut with the first team and share the dressing room with such great players.
"I bring speed and power to the team, but I know that I have to keep improving to be a complete player and be able to compete with these guys.
"I will do my best with the B team and if Luis Enrique calls me I'll be happy to help."
