Saints will review the way they rehabilitate Michael Obafemi after the striker suffered another hamstring injury just 20 minutes into his long-awaited comeback.

Ralph Hasenhuttl was pinning a lot of his hopes on the pacy 18-year-old to help lead Saints to safety with Danny Ings still ruled out.

After two months missing with a hamstring problem, Obafemi was introduced as a half time sub with Saints trailing Arsenal 2-0 at the Emirates.

But his role was to be short-lived as he quickly pulled up with a similar problem.

Hasenhuttl believes the issues are being caused by the player’s posture and that Saints must work on that in the future, but for now his likely absence for another period of time could be costly.

He said: “I wanted to give Michael Obafemi a chance to play again because he was fit again.

“It is very disappointing that he is again injured.

“It was his first 20 minutes after a long long break.

“It seems again that it is a hamstring problem that he has.

“It is a problem he knows he has with his body because of his body shape and the posture is a very stiff one.

“We must change the treatment for the future because in this situation we see it doesn’t work what we try to do with him.

“It’s absolutely disappointing and it’s horrible for me because with Danny Ings we have another striker who is out.

“He showed in this 20 minutes that with his speed he can help us and it’s not everybody concentrating on Reddie because we have another one who is quick and can come behind the last line so it’s very disappointing.”

Hasenhuttl may now need to call upon Shane Long again, despite having left the striker back at home for the trip to Arsenal.

Sam Gallagher was also left out of the squad with Charlie Austin the only other out and out striker fit and available for the upcoming matches against Fulham and Manchester United, with Nathan Redmond having started in that role against the Gunners.

That is unless Obafemi makes a remarkable recovery.

When asked how long Obafemi would be out for, Hasenhuttl replied: “I don’t know at this moment. We have a look.

“It’s a little bit different. It’s not the same muscle, it’s a little bit different.

“But every time you see it’s another muscle that makes the problems and I don’t know.”

Hasenhuttl also pulled a surprise by dropping Alex McCarthy for Angus Gunn, despite having recently said the former was now his number one.

“I was expecting a similar game like the Chelsea game against a very dominant opponent with quick strikers to come behind the last line and he played a clean sheet and made a fantastic game,” he explained.

“He did it today also with a few very good saves and the two goals I think he had no chance to keep out.”