Former Bristol Rovers man Brunt, 23, has been out since March 2016 with a cruciate ligament injury.
He has scored 13 goals in 57 appearances for the Pilgrims, but is out of contract this summer.
Ijaha, 27, has had an operation on a pelvic problem and has made just three appearances in League Two this term.
"Neither of those two will play again this season," Adams told BBC Sport.
"With six games to go, if they get themselves back into full-time training there are a good number of players that are well ahead of them so it's not going to be possible for them.
"We'll get them back to full-time training as quickly as possible and give them the best opportunity."
Plymouth are currently second in the League Two table, with a 10-point cushion in the automatic promotion places.
Manager Derek Adams has confirmed Plymouth Argyle striker Ryan Brunt and midfielder David Ijaha will not play again this season.