England will head into the second day of the third Test against India at Lord's with fresh doubts over the fitness of inspirational captain Ben Stokes.

The skipper pulled up with what appeared to be a groin issue late on Thursday's opening day, with Stokes receiving on-field treatment before he batted on until the close.

England were 251-4 at stumps, with Joe Root 99 not out and Stokes, who won the toss, unbeaten on 39.

The 34-year-old Stokes's career has been blighted by injuries, with a longstanding knee problem requiring an operation in 2023, while the all-rounder has suffered two serious hamstring tears during the past eight months.

In an encouraging development for the side, Stokes has been able to operate as a fully fledged all-rounder in recent games after his fitness issues restricted his impact as a lively seamer.

But such is his importance to the balance of the team, with England currently 1-1 in a marquee series at home against India as they build towards a showpiece Ashes tour of Australia, that team chiefs will hope Thursday's incident is merely a minor problem.

"Fingers crossed it's nothing too serious and he can do something magic and come back strong," said England vice-captain Ollie Pope. "We'll see how he pulls up tomorrow (Friday).

"We've got a big Test over the next four days and we've got a big two coming up after that so it's important to try and manage him.

"That's one of my roles, to make sure he doesn't push himself to a ridiculous place with whatever he's dealing with at the moment.

"I'm sure the physios and medics will work with him to lay out a plan and I'll help push him in the right direction," added Pope, who made 44 on Thursday.

Play ended with Root just one run shy of his 37th Test hundred and a record-extending eighth such century at Lord's.

Pope, however, does not expect the star batsman to suffer too many nerves overnight.

"Obviously he'd have loved to have a hundred red (not out), but he's got 36 of them, so I don't think he'll be too sleepless," said Pope. "He'll get his head down.

"It would have been nice to see him get it tonight but he'll be looking at the bigger picture and trying to make it a monster innings. Hopefully we can kick on and get 400, towards 500."