Callejon sustained an ankle injury in Madrid's 1-1 La Liga draw against Villarreal on March 21, and was taken off at half-time of the meeting at El Madrigal.
The 25-year-old had since been out of action and consequently missed the 5-1 Primera Division win over Real Sociedad, as well as the 3-0 Champions League victory over APOEL.
Nevertheless, Madrid have revealed on their official website that Callejon has resumed individual training action, and performed some ball work with recovery specialist Carlos Lalin on Thursday.
Callejon will not be match fit in time for Saturday's match away against Osasuna, but Madrid are hopeful that he will be able to feature versus APOEL on Wednesday or the subsequent La Liga clash against Valencia on April 8.
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