Defender Westwood and midfielder Bloomfield both missed the 1-0 win over Brentford last Tuesday with hamstring injuries but could make a speedy return at St Mary's.
Winger Matt Phillips is also close to a return from a muscle strain as the Chairboys look for a third straight win.
However, defender Leon Johnson is beginning a lengthy lay-off after an operation to cure a long-standing hip problem and midfielder Lewis Montrose is also out after surgery on his knee.
A win over the Saints could see Waddock's side climb above Alan Pardew's team to move clear of the relegation zone.
