Roy Keane yesterday explained his reasons for putting Liam Miller on Sunderland's transfer list, saying the midfielder's main failing was being late for training.

Despite seeing Miller become one of Sunderland's most important players in their battle against relegation, Keane revealed ahead of tomorrow's crucial game at bottom-of-the-table Derby that he could no longer tolerate the Republic of Ireland international's time-keeping.

In his first season as manager of Sunderland last year, Keane instructed the driver of the team bus to leave without three first-team players before a trip to Barnsley and dropped them from the starting line-up because they were a minute late for the scheduled departure.

But the former Manchester United captain has come down even harder on Miller.

"I don't go around with a stick, threatening people. We have given players the benefit of the doubt but enough is enough. There comes a time when you have to say 'Move on'. Liam is very happy here but if you can't get in on time for training then it doesn't matter if he is happy or unhappy."