Manchester United's new midfielder Casemiro could make his debut at Southampton on Saturday, but Anthony Martial has been ruled out with an Achilles injury.

Casemiro has moved from Real Madrid to Old Trafford in a £60 million ($71 million) deal and was presented to fans prior to Monday's 2-1 win against Liverpool.

United manager Erik ten Hag on Friday said the 30-year-old Brazilian could feature for the first time in this weekend's trip to St Mary's.

However, France striker Martial is absent again, having missed the first two Premier League matches with a hamstring complaint.

The France forward returned as a half-time substitute against Liverpool and provided the assist for Marcus Rashford's goal, but an Achilles issue means he is absent again this weekend.

"Casemiro is fit. He did all the training sessions. He trained first individually and the last days he trained with the team," Ten Hag told reporters.

"Martial came out with a problem on his Achilles, out of the game, so we have to wait.

"I cannot tell a prognosis, how long it takes. I hope he will be available for the next game."

Martial's absence underlines the paucity of central attacking options for Ten Hag aside from unsettled star Cristiano Ronaldo, who is reportedly keen to leave the club.

United have been linked with Ajax forward Antony as well as a new back-up goalkeeper.

Asked if he expects it to be a busy week in the transfer market, Ten Hag said: We need players, clear, but we need the right players. 

"That is what we said the whole transfer window and we are happy with what we did until now but the barrier has to be high."

There was a tense moment after that question as a television reporter saw his attempts to ask a question to Ten Hag in the press conference cut off.

The journalist in question doorstepped the Dutchman during his time at Ajax and at United's final game of last season at Crystal Palace.

With his focus on the Southampton match, Ten Hag hopes United can maintain the spirit they showed against Liverpool after embarrassing losses to Brighton and Brentford.

"The spirit was already good but now it's even better," he said.

"It's clear but it's one game, so we have to build further on, we have to develop and I think everyone is aware of that."