Argentina head coach Edgardo Bauza says Lionel Messi is desperate to return to action as soon as possible.
The 29-year-old has been sidelined since being forced off in the second half of Barcelona's 1-1 draw with Atletico Madrid on September 21, during which he suffered a groin strain.
Messi, who announced his retirement from international duty after Argentina's Copa America Centenario final defeat to Chile only to reverse that decision, was left out of the squad to face Peru and Paraguay in this month's World Cup qualifiers as he continues his recovery.
Bauza admits that the five-time Ballon d'Or winner is anxious to be over his latest muscle problem, but has once again warned that both club and country must do their utmost to keep him fit in the coming months.
"Messi is worried about his injury. He wants to play the games and it's difficult to have him sidelined," he told TyC Sports.
"We never toyed with the option of having him in this squad. We have to be careful together.
"Barcelona's medical staff know perfectly what he has to do, I simply say that he has to look after himself.
"He's now in the recovery process, which is good news. I think he'll be at a good level when he returns."
Argentina failed to win any of their first three qualifying games for Russia 2018, but a run of four victories in their last five has taken them to third in the table, a point behind leaders Uruguay.
Bauza concedes that Messi will be missed over the next two matches, but is confident that he boasts a squad strong enough to take maximum points from the upcoming games in Lima and Cordoba.
"We don't have the best attacking player there is, so you have to put other options in to find that cutting edge," he said. "But Argentina can find it, because we have very good players."