The West Ham United right-back, on loan from Arsenal, reported to St. George’s Park on Sunday after playing 90 minutes for the Hammers in their win over QPR earlier that day.
England U21s v Croatia U21s
UEFA Euro U21 Championship
Play-off first leg
5.45pm, Friday 10 October 2014
Molineux, Wolverhampton Wanderers
Live on BT Sport
Call 0871 222 1877 for tickets
But having missed most of the season so far with a hamstring injury before that, the Three Lions medical team are keeping a close eye on Jenkinson ahead of the first leg at Molineux.
"Sunday was his [Jenkinson’s] first game back since he was out with a hamstring injury," said head coach Gareth Southgate.
"Because of the recovery from the injury but also because of the first 90 minutes he had back, means he’s still recovering.
"It’s one that we’ll be quite careful with because on the back of an injury and having played his first 90 minutes, he would be unlikely to play two 90 minutes for us.
"So we will have to assess him, but as long as he feels comfortable with everything and he’s ready to train, he will do some sort of training but not fully with the team just yet."
Manchester United defender Luke Shaw also reported on Sunday after earlier being substituted with a knock to his knee in the Reds’ 2-1 win against Everton at Old Trafford.
The 19-year-old trained with the Three Lions on Tuesday though and Southgate is pleased to have him back in his group.
"Luke’s absolutely fine and he followed the programme we would have for him on the back of him playing on Sunday," he added.
"We have one or two minor niggles otherwise."
Gareth Southgate speaks to media ahead of the Croatia game