India brought in leg-spinner Yuzvendra Chahal as concussion substitute for Ravindra Jadeja in the first T20I against Australia on Friday, a decision that appeared to irk Australia head coach Justin Langer who was seen discussing the issue with match referee David Boon at the Manuka Oval.Jadeja was seen limping immediately after being hit on the head by a Mitchell Starc delivery in the 20th over of the Indian innings. The all-rounder had also taken a break after the third ball of the 19th over and his injury, which looked like a hamstring, had to be tended to.Jadeja made an unbeaten 23-ball 44 with the help of five fours and a six. The injury, however, did not impact his big-hitting as he hit 24 off the next seven balls he faced to take India to 161/7. But the way he walked off the field after the innings did not make for a pleasant sight."Ravindra Jadeja was hit on the helmet in the final over of the first innings of the first T20I. Yuzvendra Chahal will take the field in the 2nd innings as a concussion substitute. Jadeja is currently being assessed by the BCCI medical team," BCCI confirmed in a tweet.The left-arm spinner, whose 44 on Sunday is now the highest score for an Indian batsman at No. 7 or below in T20Is, was seen limping off the field.Jadeja's unbeaten 66 against the Aussies in the final ODI on Wednesday was also responsible for taking India to a match-winning 302-run total. He had also picked the important wicket of captain Aaron Finch in that last ODI.