SYDNEY - Australia will not consider Bernard Tomic for their Davis Cup tie against Taiwan in February because of doubts about his commitment, Tennis Australia said on Thursday.

Tomic, 20, was dubbed "Tomic the Tank Engine" this season after appearing to give up towards the end of a string of matches as he tumbled from a career-high world number 27 to his current ranking of 52.

"As a team, we just felt that part of the commitment that we make to athletes and athletes make to the sport is they always put 100 per cent commitment and effort in competing for their country," director of tennis Craig Tiley told the Tennis Australia website (www.tennis.com.au).

"It's not one specific incident, just an aggregation of his approach to the game ...

"We just felt that this decision should provide additional motivation every time he walks on the court to be a total professional in his approach to not only his preparation but competing in the match and post-match.

"And it would be no different if he was the number one player in Australia, or the number one player, or a junior."

Tomic's late season slump lost him the title of Australian number one with Marinko Matosevic taking over as the country's top ranked player.

Australia, who lost a World Group playoff to Germany in September to extend their stay outside the Davis Cup elite, face Taiwan in a Asia-Oceania Group 1 tie in Kaohsiung from Feb 1-3.