"Junaid was feeling dizzy after he came to the dressing room and we have taken him to hospital for precautionary check-up," Pakistan team manager Moin Khan told reporters.
"He is under observation and a head scan has been taken."
The left-arm paceman, who took five wickets in Sri Lanka's first innings, did not take the field during Sri Lanka's second innings as Pakistan were reduced to three frontline bowlers.
Junaid was hit on the left side of his helmet and continued to bat after receiving treatment on the field to remain unbeaten on 13.
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