There had been fears that King had picked up a serious arm injury in the 2-1 home defeat to West Brom before the international break.
However, the 21-year-old featured for Wales in their 3-0 demolition of Scotland and should play against the Pilgrims on Saturday.
But fellow midfielder Matt Oakley will definitely miss the match after picking up a one-match ban for collecting five yellow cards.
Therefore Nicky Adams, Paul Gallagher, Dany N'Guessan and Lloyd Dyer will all be vying for the two spots alongside King and Richie Wellens in midfield.
Aleksandar Tunchev and Stephen Clemence are still ruled out with long-term injuries.
Plymouth bid to extend their unbeaten three-match Championship run boosted by the return of skipper and central midfielder Carl Fletcher.
Fletcher returns from a one-match suspension, having sat out the 2-1 win over Doncaster in their last outing before the international break.
Argyle boss Paul Sturrock does wait on the fitness of other key players, though, including wingers Alan Judge (knee) and Craig Noone (foot).
On-loan Blackburn ace Judge was substituted after scoring in the Doncaster success.
Noone - who featured as a substitute against Rovers - was substituted during Tuesday's 1-0 reserves defeat by Swansea and faces a race to be fit.
Argyle also wait on the fitness of on-loan Manchester United right back David Gray (hip).
Sporting Life