The pair were part of manager Michael O'Neill's first 24-man squad since taking over from Nigel Worthington, but were ruled out with injuries as the players met up for training in Belfast.
Blackpool's Cathcart, a strong contender to start the match, has a hamstring complaint, while Plymouth forward Feeney failed to overcome a calf problem.
No replacements have yet been named but with the under-21 side not in action this week, O'Neill has several options should he wish to strengthen his squad.
Source: PA
Source: PA