Flanker Dougall sustained a mild ankle sprain, while centre Downey irritated his groin - both players are expected back next week.
James Cronin did not train today after taking a knock to his lower back and he will undergo a scan early this week to further assess the injury.
Keith Earls also missed today's training session with a bruised shoulder and he will be monitored as the week continues.
Development hooker Niall Scannell, who made his starting debut last Friday, will take part in limited training after hyper-extending his left elbow, and the same applies for Johne Murphy (tight calf) - but both players are expected to train fully later in the week.
Duncan Casey, David O'Callaghan and Tommy O'Donnell all returned to full training after following return to play protocols after the Scarlets game, while BJ Botha (knee) also resumed full training today.
As expected, Felix Jones (neck spasm), Ian Keatley (hip/dead leg) and Damien Varley (illness) are back training this week.
Continuing with their own rehab programmes are Conor Murray (knee), Simon Zebo (foot), Luke O'Dea (thumb), Mike Sherry (knee), Niall Ronan (knee) and Donnacha Ryan (knee).