The England forward was absent altogether for Saturday’s 2-0 win over Wolves at Old Trafford having suffered a leg issue during the narrow loss at West Ham last week.
Ten Hag revealed on Friday that Rashford was “more than doubtful” for the visit of Julen Lopetegui’s side and he did not even make the bench in the end.
And while United crucially returned to winning ways without him thanks to goals in each half from Anthony Martial and fit-again substitute Alejandro Garnacho that earned vital breathing space in the top-four battle with in-form Liverpool and Newcastle, they would certainly like to have their attacking talisman back for the season run-in.
The Red Devils see out the Premier League campaign against Bournemouth, Chelsea and Fulham before the small matter of an FA Cup final derby against Manchester City at Wembley on June 3.
“I can’t tell [what the latest is] in this moment. He is not available,” Ten Hag, speaking just before the win over Wolves, said of Rashford, who needs just one more goal to become the first United player to hit 30 across all competitions in one season since Robin van Persie did so in 2012-13 - Sir Alex Ferguson’s final campaign in charge.
“So for this moment, we have to focus on the team who is available. We have a good team and it’s a good squad. We have to win this game.”
Asked if that latest problem could keep Rashford out for a while, Ten Hag added: “I can’t tell in this moment and as I say, it’s not my focus point in this moment.
“I hope [he will be back soon]. Of course. And he will do everything that can be done.
“The medical staff is working hard on it, but I am focused, and my team are focusing, on this game.”
Ten Hag had better news on Scott McTominay, whom he said was “on the way back” from his own injury problems that have kept him sidelined since he scored in the 2-0 win over Everton on April 8.
“He’s made really good steps,” said Ten Hag of the Scotland midfielder. “He’s close, but not close enough to make the selection for today.”
United remain without the likes of long-term absentees Lisandro Martinez, Donny van de Beek and Phil Jones, plus goalkeeper Tom Heaton.
Bayern Munich loanee Marcel Sabitzer has also picked up an injury and joined Rashford on the sidelines for Saturday’s win over Wolves.