LeBron James has admitted that he is unhappy with the strength of his Cleveland Cavaliers side after they lost their second straight game with a 104-99 defeat to Detroit Pistons on Tuesday.

The Cavaliers have started the current season 8-3, a record which is level with that of the Chicago Bulls at the top of the Eastern Central Division heading into Thursday's game against the Milwaukee Bucks.

However, James said that his side are still lagging some way behind the best sides in NBA and suggested that they need to toughen up if they are to challenge for titles this season.

"We are too relaxed and too nice," James told reporters. "We are just too nice. It is not always about being Iron Man, it is a mental toughness as well, going out and doing your job, doing it at a high level and preparing that way before the tip even happens. So we have got some guys who will do it and some guys that do not do it consistently enough.

"You cannot play down to the competition at this point because we are not better than [anyone] in the league. We have got so much work to do at this point. We are not entitled to a win. We are not entitled to being the Eastern Conference champions. It is a totally different year, and until we figure that out, we are going to continue to put ourselves in positions to lose basketball games.

"Our job is to do the dirty work and do the little things. So definitely myself and the rest of the bigs, we have got to challenge ourselves. It has got to come from within sometimes, words can only go so far. We have the ability to be a great team, but right now, we are not a very good team. We do not pay attention to details as much. We do not go out and battle when we are supposed to."

Four-time NBA MVP James rejoined the Cavs for a second spell in 2014 after previously playing for the franchise between 2003 and 2010.