Flying winger Zane Banton and midfielder David Diedhiou won’t play again this term.
The Saints’ maintain play-off hopes and are back to within striking distance of the top seven.
But this double dose of bad news is a set-back to their promotion hopes.
“We’ve been desperately unlucky with injuries this season,” said the former Arsenal star Allinson.
“I’ve not known anything like it in my time here.
“It’s a great shame for Zane as he’s been our most consistent performer since Christmas
“We already have David Noble and Clovis Kamdjo on the treatment table so to have Davis Diedhiou ruled out for the rest of the season has really stretched the squad.
“I’m going to have to look at bringing a player or two in to help us out but as you can appreciate it’s the business end of the campaign and clubs are reluctant to let their better players go.
“We’ll keep going no matter what and the I know the lads that are fit will be giving their absolute best for the remaining fixtures,” he told the club’s website.