England fast bowler Gus Atkinson was substituted out of a County Championship match on Sunday and later failed a concussion test after being hit on the helmet twice while batting, raising concerns about his fitness ahead of next month's test series against New Zealand.
The seamer was struck twice on the head by international teammate Josh Tongue in Surrey's match against Nottinghamshire but initially continued batting after on-field assessments.
The 28-year-old later called for further treatment before retiring hurt on 27.
"Obviously, he failed a concussion test, that's why he is out of this game," Surrey head coach Gareth Batty said in a video posted on the team's Instagram page.
"He felt like he was OK, but duty of care comes into it. We will keep an eye on him now and make sure he is healthy."
England are scheduled to host New Zealand in a three-match test series beginning at Lord’s on June 4.