BOSS Ralph Hasenhuttl challenged fit-again Stuart Armstrong to show he can be the influential player he was for Saints last season again this time around.

The Scotland international this week returned to training, following a troublesome calf injury.

Armstrong has not featured for Saints since pre-season due to the issue.

But he may be involved this weekend, when Saints head to Chelsea, seeking a first Premier League win of the season.

This campaign has seen the likes of Mohamed Elyounoussi, Moussa Djenepo, Nathan Redmond and Theo Walcott fill the attacking roles in which Armstrong will look to force his way in to.

And despite providing five goals and six assists, as well as filling in in a deeper midfield role last season, Hasenhuttl has hinted Armstrong will not walk straight back into the side.

Asked how much Saints have missed the Scot in recent months, boss Hasenhuttl said: "It is always good when you have everybody on board and can select what qualities you need.

"I think Stuey had a tough pre-season and then with the injury it took much longer than we all expected.

"It was a big setback for him personally also. In football, when you are not part of the sessions and you cannot develop yourself, then it’s tough to come back.

"I think it’s important now for him that he sees he has to work hard to come back in the team."

Hasenhuttl added: "Yes, I know that he can score goals. Yes, I know that on the 10 position he is a player that was important for us in the past.

"On this level he has to come back. There is a lot of work to do for him I think.

"Hopefully he sees this and he invests everything so that he comes back to the level he has been."