Martinez' interviews this week hint that he will stick with Howard for his experience and 'leadership' qualities, but you'd expect Joel to start in the following two (cup) games. Given Howard's recent form, the worsening relationship between him and the fans, and the amount of press attention on him at the moment, if Joel puts in two good performances in the cup games I hope that would be the ideal opportunity for RM to let him keep his place for the following league games. If he's ever going to do it, surely that would be the time?
Of course, Tim could put in a worldie performance against Spurs... (I hope he does!)