British and Irish Lions full-back Liam Williams is a doubt for Wales' opening autumn Test against New Zealand.
Williams has trained with Wales but has not played for Scarlets this season since having his appendix removed.
Wales host the All Blacks on Saturday and face South Africa, Fiji and Australia in the following weeks.
"It's important that we remember that we've got more games in November, so we have to be clever with how we use Liam," said attack coach Stephen Jones.
"Liam is back training, which is great. He's not had many sessions this season so we're trying to improve him with every session.
"He's 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.
"In fairness, we are fully aware that it would be a big ask of Liam [to be fit to face 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."
Another fitness concern is flanker Ellis Jenkins, who came off in Cardiff's game against Sharks on 16 October with a rib problem.
Asked if he was out of contention to face New Zealand, Jones said: "No, not at all. He'll be training today but it's a matter of ticking various boxes as the week goes along, running with the team, the contact element."
Wales will be severely depleted when they take on the All Blacks at the Principality Stadium.
England-based players Dan Biggar, Callum Sheedy, Louis Rees-Zammit, Taulupe Faletau, Nick Tompkins, Thomas Young and Christ Tshiunza are unavailable because the game falls outside World Rugby's international window.
Wales are also facing an injury crisis, with Josh Navidi, Justin Tipuric, George North, Dan Lydiate, James Botham and full-back Leigh Halfpenny ruled out of the entire autumn series.
"We obviously knew that was going to be the case a long time ago [England-based players being unavailable]," said Jones.
"From my perspective, I am very confident and comfortable with what we have in the playing group.
"We have a huge amount of experience, a lot of talent and there are going to be opportunities for players, which is what you want, and you want your players to make the most of those opportunities."