Palace enjoyed victory over Burnley on Saturday.
"Alan has brought great experience to the club and it is that little push that the club and us players needed around us," said Kelly.
"We needed that key figure and he has brought that and what he has done in the couple of weeks he has been with us has been brilliant.
"We are all enjoying our training, tactically we know what we are doing and we are showing that in games with the confidence we have got.
"The two draws were key to confidence before Alan came in and the three wins we have under him now is showing in our play we have the confidence and it is a great dressing to be in."