IMPORTANT Melbourne duo Brent Moloney and Jared Rivers are in serious doubt for next round's clash against Richmond after they sustained injuries during Monday's 21-point loss against Collingwood.

Moloney injured his shoulder in the final quarter, while Rivers didn't finish the match after again battling a groin injury.

"I know he's hurt his shoulder and with those things, the next 24 hours [is important], but he didn't look too good," Melbourne coach Dean Bailey said of Moloney after the match on Moloney.

On Rivers, he added: "Jared's had a bad run. He's hurt his groin and his last six weeks, he's been up and down.

"The docs have said they've got to wait and see how he pulls up the next day, but they can't really find a specific spot, so he'd be in real doubt for next week."

Bailey said it was disappointing for both players, as they have had their fair share of injuries in recent times, while he commended Moloney's recent efforts.

"I thought 'Beamer' really cracked in hard. He really led from the front and he showed some physical aggression at the ball, and he's been doing that for I reckon, if not most of the year, certainly the last five or six games," Bailey said.

"I think his aggression around the stoppages is good, and he wants to get in there and win the hard ball."