The Aston Villa striker has been included in the Belgium squad as they chase one point from two fixtures against Croatia and Wales and a ticket to Brazil 2014.
Benteke has, however, sat out Villa's last two Premier League fixtures with a hip complaint.
Lambert is understandably reluctant to see his most potent attacking weapon risked on the international stage.
He trusts Benteke to make the right call for club and country and hopes to have the 22-year-old back at his disposal for a home date with Tottenham Hotspur on 20th October.
Lambert said: "I trust Christian to do the right thing. He is probably stuck in the middle right now.
"But I've had a good chat with him and he will know himself what is the right thing for him to do. I trust him. But I won't be happy if he plays for Belgium and comes back to me injured.
"I know he wants to play and get back into it as quickly as possible but he hasn't been back on the training ground yet since picking up the injury.
"It's only when he starts to kick a ball again that the test will come and he will know himself if it feels okay and whether he is ready to play.
"Christian had to go and join the Belgium squad, I understand that. He was obligated to go because of the five-day rule where countries can prevent players from playing for their clubs if they don't report for international duty.
"If we hadn't let him go, they could have prevented Christian from turning out for us against Spurs.
"I think the rule is a mockery but I totally understand where Belgium are coming from. They are a point away from playing in the World Cup finals."