England left-back Luke Shaw was not a part of the Three Lions' main training group on Friday, raising concerns that his expected comeback could face further delays.
The Manchester United defender was included in Gareth Southgate's squad for Euro 2024 despite having not played since February 18, when the Red Devils beat Luton 2-1 in the Premier League.
After playing a key role in Erik ten Hag's first season in charge at Old Trafford, the 29-year-old endured a difficult second term under the Dutchman due to ongoing injury setbacks.
Throughout the 2023-24 campaign, Shaw managed just 15 appearances for the Red Devils across all competitions.
The United left-back was somewhat surprisingly included in the final England squad for Euro 2024, while his defensive partner Harry Maguire, who was also suffering from an injury, did not make the cut.
Southgate still hopeful of Shaw return before Euro 2024 knockouts
It is understood that Southgate's original expectation was to have Shaw back in time for England's final group-stage match against Slovenia.
The 29-year-old was listed as a substitute for the team's opening group game against Serbia but was excluded from the match-day squad for the disappointing draw with Denmark.
Speaking to the media ahead of the match against Denmark, Southgate said, "Luke won't be part of tomorrow's match.
"He's progressing as we initially anticipated. A few days ago, we were hopeful of speeding up his recovery, but he still requires more training."
However, with the player missing the Three Lions' full training again on Friday to continue his personalised recovery plan away from the team, concerns are growing over whether he will indeed take the field at all next week.
Should he not make it back to full fitness in time for the match in Cologne, the England boss will then be faced with an even bigger decision around whether or not to risk him in the knockout stages, considering he has not played a minute in over four months.
Consequently, questions are being raised about Southgate's selection decision around not bringing another specialist left-back to Germany, given the concerns over Shaw's fitness.
The England manager opted against including the likes of Ben Chilwell and Tyrick Mitchell in his 26-man squad, and currently has Kieran Trippier filling the gap left by the Man United full-back.
Shaw absence creates significant challenges for England
Speaking after Thursday's draw against Denmark, manager Southgate acknowledged that Shaw's ongoing absence has posed a significant challenge, stating: "It is clear in terms of the balance of the team that we don't have our best left-back, so that denies you that balance.
"But I think Tripps has done an incredible job for the team, his spirit and organisation and desire have helped us get over the line in the last couple of games.
"So that's in no way a criticism of him [Trippier], but it's obviously going to be different - a right foot rather than a left."
The Magpies defender typically operates on the right but has previously expressed his readiness to fill in on either flank when needed.