As top scorer Morelos began his four-match suspension following his red card in last Sunday’s Old Firm defeat at Celtic Park, Defoe made the most of his first starting appearance since February.
The 36-year-old opened the scoring with his sixth goal for Rangers since joining them in January, earning praise from his manager.
“I’m happy with Jermain because he’s been a top professional since he came,” said Gerrard. “He’s been immaculate around the place.
“When he’s come on in games, he’s given everything and his numbers have been good considering the chances he’s had.
“He won’t be too happy with me as I know Jermain better than most. He will want more minutes and I get that. I respect it.
“But, he will get a run in the team now. I told him if he plays well and scores goals he will get a run and if he continues to play well and score goals it will be interesting in three games time (when Morelos is available again).”
Rangers remain 13 points behind Celtic at the top of the Premiership table with just six games of the campaign remaining but Gerrard was gratified by their response to their Old Firm disappointment.
“It was what we needed after a difficult result at the weekend,” he added. “There has been a lot of frustration in the air over the past few days. It was the performance I was looking for and the players deserve credit.”
Hearts manager Craig Levein was dismayed by his team’s display in the absence of injured striker Uche Ikpeazu and admitted their preferred style of play is too reliant on the physical presence of the big Englishman who is expected to return for Saturday’s derby against Hibs at Tynecastle.
“It was a poor performance,” said Levein. “I just want to consign it to the bin and think about the derby.
“We will have Uche back for Hibs and we are a different team with him in it. But I can’t be relying on just one player.
“We need to get back to the gusto and determination we played with in the second-half against Aberdeen on Saturday. Tonight was really poor.
“I think a lot of it was to do with personnel and maybe I’m asking people to do stuff they are not capable of doing. Next season, for sure, we need another option when Uche isn’t in the team.”