Midfielder Powell and striker Clayton, both 17, netted in the Alex's 2-1 win over Morecambe on Saturday and Critchley believes it is only a matter of time before they depart for bigger clubs.
"With them playing for England as well, the scouts know who they are," he told BBC Radio Stoke.
"It only takes someone to think `we need to do it now, before someone else does it' and it could happen. It does happen at a younger age now.
"Depending on the size of the bid, if it was to happen, maybe it would happen sooner rather than later."