Ghana urged against Waris risk
Scans have revealed the striker has a torn quadricep and faces a race against time to be fit for the match against United States on Monday.
But Dr Prince Pambo has warned that, even if the player does recover in time for Monday's match, he will be susceptible to a recurrence of the problem.
"A striker as he is, he does a lot of runs and shooting and the power would come from the quadriceps muscle," footy-ghana.com quote him as telling 103.5FM .
"By the 16th (when Ghana play the United States), he might have had quite some healing but it would be a fresh healing.
"Any force you apply to this would be quite antagonistic to whatever we want from the player."
As well as the United States, Ghana face Germany and Portugal in Group G.