Diego, along with striker Derlei, defender Pepe and winger Maciel, were banned from training with the rest of the squad on Sunday, club spokesman Acacio Valentim, told national news agency Lusa.

The four were due back at club headquarters on Friday but Diego, Pepe and Derlei only showed up at training on Sunday while Maciel, whose brother has reportedly been shot in Brazil, has not returned.

"It is not right to be late but we are going to talk now to see what can be done," Derlei told TSF radio.

Meanwhile, Sporting Lisbon are still without their Brazilian striker Liedson, the leading scorer in the league with 12 goals, who has yet to return from his vacation in Brazil.

He was due back on Tuesday.