Reading striker Shane Long has been fined for his reaction to being substituted in the 2-1 defeat at Liverpool.
Long was replaced by Dave Kitson just past the hour mark in last weekend's game at Anfield and threw his shirt to the ground as he walked off the pitch.
The Republic of Ireland international has since apologised for his tantrum and Reading boss Steve Coppell does not expect to witness a repeat.
"It was unacceptable behaviour," Coppell told the Reading Evening Post. "In football now you need a 20-odd-man game and it is going to get bigger next year with seven substitutes.
"It is very much a squad game and people have just got to accept the decisions.
"Nobody is ever happy about being brought off, but they have to accept the decisions that I make. It won't happen again - I can guarantee that. He will learn from it."
Coppell is also confident that Long, who has scored three goals in 23 Premier League games this season, will improve as a player for his outing against Liverpool.
He added: "Shane is 21 now. He hasn't started that many games for us, but he has been a really important part of what we've been about over the last couple of years.
"The experience of Liverpool will be invaluable to him. He's a bright boy and he will see how he can improve and I hope he can go on from there."