The 25-year London Olympian picked up a calf injury during the Black Sticks away series against the Netherlands last week and has not joined the team in Spain for the Six Nations.
Inglis was named in the side alongside fellow Southern players Blair Tarrant and Kane Russell but his spot could be in jeopardy.
"I was actually rehabbing my left ankle and obviously did a little too much too soon and ended up injuring my right calf,'' Inglis said.
"It has been a [terrible] couple of weeks.''
Inglis thinks nursing his ankle complaint put pressure on his right calf. Plus he went from "not doing a whole lot as well''.
A scan has revealed a small tear but it is a big setback. Inglis remains optimistic, though. He even argued the injury was potentially a positive omen.
"The big message is they treat patients not the scan. The average [rehabilitation] time is around four weeks.
"It is a bit of a blow but, you know, if you look back over the history of people who have won medals, about 40% of them have had an injury in their build-up.
"If you look at it from that point of view, things are heading in the right direction.''
Inglis, who lives in Auckland but grew up in Dunedin, will do everything he can to be ready in time.
"I'll be spending five or six hours a day doing my rehab and there is still quite a lot of weights I can do. And there is the pool and bike to keep up my cardio.''
Asked if there was any talk about finding a replacement, Inglis said "the signs from the coaches are that they will give me a chance to get fit''.
"I'll certainly do everything I can to make sure I'm good to go.''
Meanwhile, Inglis was disappointed to learn Southern would not field teams in the National Hockey League.
"Obviously, it is pretty disappointing. We've worked really hard to build up the team.
"When I first joined it I think we finished dead last and we've gone on to become a constant threat for the title.
"From their point of view, I know the tournament costs are rising and it is pretty tough to field teams. I understand it ... but I'm just really disappointed.''
Southern hockey is yet to explain why it pulled out of the NHL.
Meanwhile, the Black Sticks were defeated 2-0 by host Spain in their opening game at the Six Nations in Valencia yesterday.
New Zealand played well in large patches and created plenty of goalscoring opportunities but were not able to put any into the net.
With the game scoreless at halftime, Spain made the most of its chances with a 33rd-minute penalty corner goal to Pau Quemada and a field goal from Xavi Lleonart in the 46th minute.
The Black Sticks created several goalscoring chances in the final 10 minutes but were not able to put any into the back of the net.
Head coach Colin Batch said it was pleasing to be creating chances on attack but the team needed improve on execution.
"We played a pretty good game for the most part but had a few lapses and allowed them to score two goals,'' he said.
"Going forward, it's a good learning experience for us and we need to make sure we capitalise on those chances and put them into the goal.''
