"I can't speak for him but if it was me it would be tough having that ban hanging over you. But I guess you've just got to learn to zip up," Newcombe said on Monday.

The seven-time grand slam singles champion said it was great to see Kyrgios welcomed back into the Davis Cup fold for last month's tournament in Spain.

But with Kyrgios forced to sit out his singles rubber in their heart-breaking quarter-final loss to Canada through injury, he feared he may not be up to five set tennis next month.

"I thought it was great that Nick played in the Davis Cup but it's a bit of a worry that he has recurring injuries, especially around where the muscles join the joints and that's going to be an ongoing problem for him it seems," Newcombe said.

"At the Davis Cup he'd only played four sets of singles and his shoulder started to play up again and when you've got an injury like that it's hard to go out and practice a lot.