Luke Shaw was set to return to Manchester United after he suffered concussion in England's defeat by Spain as Gareth Southgate called up Ben Chilwell and Demarai Gray.
Southgate's side kicked off their UEFA Nations League campaign with a frustrating 2-1 defeat at Wembley on Saturday but concerns over their 23-year-old left-back's well-being overshadowed the result.
Shaw superbly set up Marcus Rashford's opener on his first England start since September 2015 -- an appearance that came just a week before he suffered a hideous double leg-break in a Champions League tie.
The left-back looked like he may have suffered another major injury minutes into the second half on Saturday, with his head appearing to hit Dani Carvajal's hip before sickeningly bouncing off the turf.
The impact was audible from the stands and led to him leaving on a stretcher wearing an oxygen mask and a neck brace after lengthy treatment.
Shaw was later walking and talking and tweeted he was "doing fine" but he will return to United on Monday.
A statement from the Football Association read: "Luke Shaw remained at St. George's Park today for further rest and monitoring having sustained concussion against Spain yesterday. He will return to his club tomorrow."
Shaw's injury has opened the opportunity for uncapped left-back Chilwell, who moves up from the England Under-21 squad with Leicester teammate Gray.
The pair could make their senior bows on home turf this Tuesday as the King Power Stadium plays host to a friendly against Switzerland.