Why Casillas had not featured for Porto for the past 3 games

After appearing to be first choice, the former Real Madrid goalkeeper has found himself frozen out for their three most recent matches.

"The players know what my rules are, the way I coach and how I demand that they always give 100 percent in training," Conceico told reporters.

"He talked to me and wanted to know why he isn't in the team and I explained that it was due to his training. I have to be consistent in dealing with my dressing room.

"Whether it is Joaquim, Manuel or Antonio. If I make exceptions, I'll lose the whole squad but I can't do that and close my eyes to 15 days of training like that from Iker and he understands that."

Despite newspaper reports in recent days hinting that the Spaniard could soon be moved on as a result of the situation, Conceicao laughed off those claims.

"He has shown good behaviour and is now working on improving. I'm certain he'll fight [for his place]," he added.

Casillas hasn't played since a scoreless draw with Sporting CP at the start of October.