Manchester United suffered a double injury blow in pre-season when Leny Yoro and Rasmus Hojlund limped off in a friendly defeat to Arsenal.
He Red Devils were beaten 2-1 by their Premier League rivals in Los Angeles overnight.
Hojlund had given Manchester United the lead after just 10 minutes after running onto Marcus Rashford's pass before scoring through goalkeeper Karl Hein's legs.
However, just five minutes later, he was limping away.
Joined Yoro, new signing for 52 million pounds He was also absent in the first half, as he fell off the ball and was immediately substituted.
“We'll have to wait 24 hours and then hopefully we'll know more,” Ten Hag told MUTV.
“We were very careful, especially with Leny. It's disappointing that he had to retire, but let's stay positive and see what happens.”
Gabriel Jesus scored the equalizer for Arsenal After 25 minutes, Gabriel Martinelli scored the winning goal nine minutes from time.
The two teams contested a pre-arranged penalty shoot-out, with Jadon Sancho scoring the winning goal in a 4-3 victory.
The injuries will leave a bitter taste in the mouth of coach Ten Hag, who saw the 2023/24 season ruined by injuries.
Manchester United suffered 45 separate injury cases last season, the most ever recorded in the past 20 years.
There were 21 different players who missed a total of 1,620 days.
“It's too much. We are not the only team that has had problems with injuries, other clubs have had the same luck,” he told Dutch newspaper Algemeen Dagblad in July.
“Last season we had constant injuries to players in the same positions, all in defence. At one point, we had almost no defenders available.
“When we started here, United hadn't won a trophy for six years and it wasn't because they didn't have good coaches here. That does say something about the make-up and quality of the group of players. I knew that when I started, of course, but they were players on long-term contracts.
“We were and still are in that process[of building]. If you compare our squad to other top Premier League clubs, we are certainly a bit less in terms of depth. That's exactly why we found it so difficult to deal with those injuries.”
Losing Yoro and Hojlund to injury is not ideal preparation for the 2024/25 campaign.
On Thursday they will face Real Betis and next Sunday Liverpool.
United then play rivals Manchester City in the Community Shield on August 10, having beaten them in the FA Cup final in May.
Their first Premier League game of the season will be against Fulham at home on August 16.