The Baggies right-back has started every league game this season but was forced off with injury in Saturday's 2-0 win over Crystal Palace.
Reid has featured just once this campaign - in a Capital One Cup tie in late September - but McAuley is confident the former Republic of Ireland international could easily step in should Jones be ruled out.
"He's been in and around the squad," McAuley told wba.co.uk.
"He had an injury, he's got himself back fit and he's training with us every day.
"Fingers crossed for Billy it's not too bad - but Reidy's ready to step into that berth.
"Reidy's a great pro and he's great to have around and when he plays he's fantastic for us.
"In football we all talk about the squad and it's important our squad sticks together.
"That's how it is. It's really gelled and whoever plays we want them to do well."