Four points from a home match against Albania and Monday's trip to San Marino will guarantee England' s place at the 2022 World Cup but they have been hit by a spate of withdrawals and illnesses.
Mount is recovering from dental surgery, Shaw suffered concussion in the Manchester derby, Marcus Rashford has stayed in the city to continue his recovery from injury, James Ward-Prowse and Declan Rice are out through illness. Dominic Calvert-Lewin and Patrick Bamford are injured, and Kieran Trippier, Jadon Sancho and Jesse Lingard have been dropped.
So for Grealish to fall ill too was another blow. Manchester CIty's £100m playmaker has been declared fit.
"He's had some illness and he did miss training," confirmed Southgate. "He's trained this morning with the rest of the group.
"We've had a lot of medical issues this week but he's available for the game and ready if required."
The news on Mount and Shaw was less positive when Southgate addressed the media on Thursday afternoon.
"I've got to check in with our medical staff for today's update but the longer it goes, the less likely it is," said Southgate when asked if either would feature in the next two matches.
"It's different situations, really, Mason's got to recover from dental surgery.
"Luke there's obviously very strict guidelines on concussion markers and on the first day he didn't pass the marker so it all gets shifted back.
"Rightly we've got to follow the guidelines on that. We might run out of time, we'll just have to see."
Mount's absence could open an opportunity for the uncapped former Huddersfield Town loanee Emile Smith-Rowe, a late call-up to the squad who plays in the hole or wide on the left for Arsenal.
"We've brought him here to be involved with the team and with a view to being involved in the two matches," said Southgate of the 21-year-old Arsenal player.
"He's settled really well. He knows a couple of his club team-mates, Phil (Foden) from when he was with the Under-17s and this is a group that makes new players welcome so I don't think it's a difficult environment to fit into.
"His quality has been apparent in the way that he's trained so he's ready and we've enjoyed having him us this week already."