The Blaugrana cruised to a 3-1 win courtesy of goals from Ousmane Dembele, Luis Suarez and Andre Gomes, with Sibusiso Vilakazi pulling one back for the Absa Premiership champions at FNB Stadium last night.
Dembele curled in an early opener after Bangaly Somahouro’s sloppy pass toward Tebogo Langerman was intercepted.
Suarez doubled the advantage in the 20th minute after Somahouro once again failed to get a proper connection when he was sliding to clear the ball.
Downs' poor defending cost them once again in the second period, as Ruiz de Galarreta pounced on a backpass by Hlompho Kekana and teed up Gomes to make it 3-0.
Vilakazi managed to reduce the deficit in the 75th minute after breaking free of the Catalans' defence.
“I think the difference is the Rand and the Euro, to sum it up," Mosimane said.
"Ja, when they scored the first goal in the first minute, we started to say, ‘How many goals were coming?’
"But we paid school fees tonight [Wednesday] and I think you saw that.
“I think Bangaly made a big mistake by giving the ball away and Dembele scored. I think 'Keke' [Kekana] gave the ball away and the striker [Gomes] scored. And the other goal, okay, it’s Barca, that is they way Barca plays and that was the school fees we paid.
“There’s a huge difference in terms of results and also we should have used our opportunities. I think Khama [Billiat] should have used his opportunity and Langerman should have used his also. With the keeper to beat, he decided to pass, to bring it across but in Maritzburg [against Maritzburg United in the league last month] he cracked it from far.
“But to sum it up, obviously you could see the difference. You could see the quality in Barca; you see how they pass the ball and we struggled to get the ball.”
With Barca making wholesale changes at the interval, Downs were more competitive in the latter stages of the friendly.
“In the last 10 minutes we came out from the back, playing with our centre-backs and we could move out and come out,” Mosimane added.
“There were times where they stole the ball, like taking a lollipop from the mouth of a small child.
“But we also took the ball from them, pressed them and they kicked the ball outside a few times. We pressed them, so at least we were doing something right. But it’s a big difference, let’s be honest. They are a big team.”
Downs now turn their attention to their CAF Champions League group stage match with Horoya of Guinea in Conakry on Tuesday.