The goalkeeper was rushed to hospital following the incident early into Blackpool’s 1-0 defeat to Preston North End.
The game was stopped for a lengthy period of time after the 24-year-old collided with Preston forward Cameron Archer.
Grimshaw raced off his line to win the ball at Archer’s feet after the on-loan Aston Villa man was played through on goal.
The Blackpool goalkeeper barely moved after the incident after Archer’s knee appeared to strike the head of the 24-year-old.
Grimshaw remained motionless while he was tended to by medics, before being stretchered off after an almost 10-minute stoppage.
Providing an update on Grimshaw’s condition after the game, head coach Neil Critchley said: “That was a horrible situation seeing Grimmy come off so early.
“You could tell straight away that he got caught and when he’s down for so long you’re trying to get some information and I nearly walked onto the pitch myself because I was really concerned about him.
“But he’s awake, he’s at the hospital and he’s responsive, so that’s positive news so far.”
When asked if the incident had an impact on his side’s below-par display, Critchley added: “It’s never nice when you see one of your teammates on the floor and not in a nice situation.
“He was a bit dazed and groggy and he didn’t know where he was for a period of time, but I believe he’s at hospital and he’s got his bearings a bit better.
“Hopefully we’ll get some positive news in the next hour or so.”
Grimshaw himself posted an update to social media on Wednesday morning.
He wrote on Twitter: “Thank you for all the messages of support. I’m feeling okay. I’ll be back as soon as possible.”
The former Manchester City man, who has been excellent for Neil Critchley’s side this season, was replaced by former PNE shot stopper Chris Maxwell.
The 31-year-old was booed as he made his way onto the pitch having departed Deepdale in 2020 to join their fierce rivals.
New concussion protocol meant that Blackpool were permitted to make a fourth sub.
Archer would end up scoring Preston's winning goal in first half stoppage time, when 11 minutes were added on.