Adelaide United are not stressing about Brazilian defender Cassio's supposed 'walk-out' from training yesterday.

The left-back left the Adelaide camp in a huff, citing the attitude of his teammates as the reason for his sudden departure.

It was the second time in a matter of days that the Reds have had to endure a fracture after midfielder Paul Reid withdrew from the squad for the knockout final against Wellington Phoenix on Friday.

But captain Travis Dodd said Cassio's attitude was fine and does not expect any further repercussions as the players prepare for Sunday's clash with Gold Coast United.

"With Cassio's situation, I'd rather see him fired up like that than walk around and not care what the other players are doing," Dodd told the Adelaide Advertiser.

"It's good that he gets fired up. We'd finished the session anyway, so I would hardly say that he walked out of training."

And head coach Rini Coolen concurred with his skipper's sentiments.

"I know there is a lot of attention on something small that happened at the end of training," Coolen said.

"To be honest I was very happy with the session yesterday. One team was smashed at training. Cassio was a member of that team.

"He made in my opinion one mistake, leaving the pitch without telling me. We spoke about that this morning and he apologised."