Wales full-back Liam Williams is a doubt to face New Zealand in the Autumn Nations Series on Saturday.
Williams, 30, took part in training last week but has not played since he became a two-time British and Irish Lion on the tour to South Africa after having his appendix removed.
Wales also host South Africa, Fiji and Australia in the following weeks next month.
"Liam is back training, which is great. He has not had many sessions this season, so we are trying to improve him with every session," said Wales attack coach Stephen Jones on Monday.
"He is working very hard because he wants to play and he wants to prove that. But we, as coaches and fitness coaches, understand where he is.
"It is important that we remember that we've got more games in November, so we have to be clever with how we use Liam.
"In fairness, we are fully aware that it would be a big ask of Liam (to be fit for New Zealand), but he is doing everything he can to be available. He is ticking every box, but you do need some volume in the legs as well."
Wiliams, who has won 71 caps, is the latest in the line of players set to miss the game against the three-time world champions for Wayne Pivac.
Wales will be without England-based players like Dan Biggar, Taulupe Faletau and Louis Rees-Zammit because the autumn opener falls outside World Rugby's international window.
Williams' fellow Lions George North, Josh Navidi and Justin Tipuric are also all unavailable through injury.
Gareth Anscombe, who has not played Test rugby since suffering a serious knee injury in August 2019, and Rhys Priestland - last capped internationally in 2017 against the All Blacks - are expected to vie for the fly-half starting berth.
"They are both training very well, and both those guys will be looking forward to getting back in the stadium in front of a full house, which is going to be special for all of us.
"Gareth is obviously a very knowledgeable player, he understands the game inside out and is very driven, which you have to be to have come back from an incredibly tough injury.
"It is a huge credit to his professionalism and his attitude. He has been excellent in training, he sets high standards and has been a pleasure to work with.
"Rhys' decision-making has always been very good, he has always been smart on the ball. Regarding his kicking game, we know that is top-drawer.
"But, for me, it's his decision-making on the ball and bringing others into play. Rhys has demonstrated that with Cardiff this year."
Wales have not beaten New Zealand since 1953 and lost the last 31 Tests - 16 of those in Cardiff - against them.
Meanwhile, the Welsh Rugby Union confirmed Alex Cuthbert has been called into the squad.
The 31-year-old former Exeter wing, who now plays for the Ospreys, won the last of his 47 caps against Georgia in 2017.