I think not, but his position is definitely threatened.
It is likely that Argentina will continue not having a suitable #9, but it is necessary to deploy such player even if he isn't on par with Tevez in term of skills and speed. The physical attribute of height is by itself a very important quality after all.
Consider this:
Aguero is more used to the center forward role and he's on form. He's tied with Messi for 2nd place on the goalscorer list in Spain. So even if Crespo wasn't hurt, Denis isn't the only alternative.
Tevez could perhaps consider dropping into a more defensive role. I think he would do better than Cambiasso on the left. He has those attributes to become a great winger. He's strong, has good acceleration, shoots well from long distances, tackles well, aggressive and always fights for the ball, has great vision for passes... The best players can play different positions. Cruijff, Beckenbauer, Diego...

Due to Crespo's ankle injury, Tevez will probably start this weekend.
I do hope to see Aguero more than 20 minutes. Get him an international goal. I'm sure all the guys are more than happy to set him up. We need to give everybody pitch time so when we go to South Africa, it would be a well synchronized team instead of just brilliant individuals.
We are building a team to win both the olympics and world cup.