Hooker McBryde has been in impressive form for Llanelli Scarlets this season, but is struggling with a back injury, while Celtic Warriors second-row Sidoli has been hampered by a niggling groin problem since he returned from the Rugby World Cup in Australia.
"We are hoping they will be okay," said Wales Team Manager, Alan Phillips. "We will reassess the pair of them. If they are struggling, we will look at our options then.
"Steve Hansen has a pretty strict policy on this and likes to make a decision earlier in the week, rather than later. We want to have the right preparation and we won't leave any decision to the last minute."