The incident happed in a T20 Blast fixture between Birmingham and Warwickshire.
Pakistan vs England: Haider Ali played a pull shot off Richard Gleeson and it hit umpire Aleem Dar on the thigh as he tried desperately to get out of the way.
After winning the first T20I by 63 runs, Pakistan will now look to take an unassailable 2-0 lead in the three-match series with a win in the second game against the West Indies.
Mohammad Rizwan and Haider Ali powered Pakistan to 200 for six. The visitors were never in hunt of the target as they were dismantled by a superior Pakistan bowling attack and folded at 137 in 19 overs.
T20 World Cup: The three players who were in the original Pakistan squad and are now left out are batsman Khushdil Shah, deputy wicketkeeper Azam Khan and pacer Mohammad Hasnain.
PAK vs ZIM: Pakistan defeated Zimbabwe by eight wickets in the second Twenty20 International in Rawalpindi to take a 2-0 lead in the three-match series.
Shoaib Akhtar said he has had "some discussions" with the Pakistan Cricket Board over taking on the chief selector's job.
Haider Ali marked his international debut with a half-century as Pakistan defeated England in the 3rd T20I.
Shoaib Akhtar praised Haider Ali, who stitched together a 100-run partnership with Mohammad Hafeez for the third wicket as Pakistan defeated England in the 3rd T20I.
It was Pakistan's first victory in 66 days of being in a bio-secure bubble in England amid the coronavirus and meant they squared this three-match T20I series at 1-1.