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Richmond duo Brett Deledio and Ben Griffiths are both in doubt to face Collingwood on Sunday afternoon.

Richmond coach Damien Hardwick said that Deledio is no certainty to play this week despite returning last week against North Melbourne.

"He's pulled up OK. We'll see how he goes through training today (Thursday) and hopefully he can play a full game this week," Hardwick said.

"The fact of the matter is that he's got an injury that at various stages we're not quite sure of the consistency of how it pulls up after every game which is frustrating from Brett's point of view and ours.

"We've got to take it on a week-by-week basis at this stage."

Deledio managed about 70 minutes of game time against the Roos last weekend, in his first match since injuring his calf in round one.

Key forward Ben Griffiths is also in doubt after suffering from concussion against the Kangaroos.

Griffiths will undergo a concussion test to prove his fitness before being named in the squad to face Collingwood on Sunday.

Former captain Chris Newman will also be monitered after injuring his hip-flexor against North Melbourne.

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