Sounds like he is OK from this interview he gave in Argentina:
http://www.ole.com.ar/seleccion/titulo_0_1666033422.html
Here's the Google translate of the relevant bits:
Now you go again with a muscle problem. Is a remnant of that made you lose the double FIFA date before?
No, no. This injury is now hit the City in the match with Celtic for Champions: It was hard, it had rained bad, the grass was high and muddy, and from there came a little overhead. I recovered well two days after I played against Tottenham. And I traveled.
'What happened to you?
' Sometimes does not help the issue of travel: rest, the schedule change ... But I'm pretty good. I wanted to play in Peru, be available and put up with everything I could. When you're on the team you always want to be, but the last time, for wanting to, I ended upinjuring against Ecuador. One sometimes thinks: "Why not stop?". Because then I'm a half months out and I lost six or seven games in the City. But when they call for the selection you want to play as. It is so.
-¿Llegás For the match against Paraguay?
Much better I am. Peru after the game had two days to recover and today (yesterday) I made a little football. I'm quite well. Luckily I went the pain I had before Peru was in the adductor and certainly to protect the adductor I loaded a little soleus. I'm better: we did studies, got well and I'm trying to get as fresh as possible for Tuesday.