"We've been fortunate," he admitted. "We went down to 10 men in our last away game and we can't keep doing that."
Coppell felt some sympathy for Kebe but said he was wrong to raise his hand to Souza.
"The centre-half tried to claim some ground and my player responded by pushing him away so it was a nothing situation," said Coppell. "That's no defence because you can't raise your hands but we know what we think and we'll keep our thoughts to ourselves."
Reading had to contend with arriving late at the ground after their coach broke down on the M1, forcing a delayed kick-off.
"The bus started spewing out smoke and we were stranded," Coppell explained. "Barnsley were fine about putting the kick-off back and we thank them for that."
"It's very disappointing," said Barnsley boss Simon Davey. "They stuck 10 men behind the ball and we couldn't break them down. Credit to Reading because we gave them a chance to score and they took it."