The England U23 player sustained an ankle injury in the 5-1 triumph over Notts County, which required an operation.
Manager Nick Cushing and captain Steph Houghton have already expressed their disappointment at losing the Prestwich-born starlet.
Though naturally saddened to be missing the climax of the season, centre-back McManus is adopting a positive mental attitude.
“Of course, I’m gutted to be missing the rest of the season,” she stated. “I’d kept my shirt at centre-back and we’d been doing so well - defensively, with so many clean sheets as well as on the attacking front.
“I jumped up for a header with Rachel Williams and unfortunately, I landed on my ankle, half-landing on her foot which has rolled it outwards.
“I heard the crunch and I knew straight away something wasn’t right.
“It’s disappointing to be injured when we’re on such a good run but for me now, it’s a personal battle to get back playing.
“Me and Steph have a good understanding, playing next to each other in defence. I’d have loved for that to continue but now I have to concentrate on getting myself back out there.
“I’m keeping positive. I’m in the best place for recovery and I’ve had a lot of support from the people around me. I’m in safe hands.
“I had surgery and the surgeon told me everything had gone really well. I have a few days rest now and rehab will begin on Friday.”
McManus added she is inspired by those around her who have shared similar experiences.
She explained: “Keira Walsh has had this injury twice since she joined and now she’s back playing - that’s filled me with confidence I can do the same.”