Lafferty, 31, came off the bench to score in the 5-0 win over Hamilton on Sunday.
Ryan Jack, Jermain Defoe, Scott Arfield and James Tavernier had all scored to put Rangers four up at half-time but Sutton was left questioning the man who scored number five.
“He came on and made a bit of an impact but I think he’s been frankly disappointing in a Rangers jersey.,” Sutton said on BT Sport.
“I think he’s just onside and this goal will do him the world of good.
“He really needs to step up. I don’t think Steven Gerrard really trusts him but there is – and we’ve seen over the years – a player in there somewhere.
“Clearly he’s third choice as a centre-forward for Rangers.”
Stephen Craigan was working alongside Sutton for BT Sport and he revealed he had spoken to assistant Gary McAllister about the man in question.
“Lafferty iss popular amongst the staff. I was speaking to Gary the other day and he said he’s good for the dressing room, good around the place and everyone is desperate for him to do well,” Craigan explained.
“The general consensus is him scoring would have been popular.”
Gerrard hailed Lafferty after the match but he was fuming with some of his team-mates for an apparent lack of respect by showboating.
“Kyle deserved that. He’s been unlucky at times. That’s what we need Kyle to do if he’s been a reserve,” Gerrard said.
“We need him to come on and contribute and that’s what he’s done.
“I thought the subs were good. It was good to get Kent and Arfield off the pitch, to look after them.
“You ask the subs to provide some energy because it got a little bit flat in the second half.
“That’s normally, I think mentally a few switch off and get a bit comfortable and showboat a bit and I don’t like that.”
Rangers closed the gap on Scottish Premiership leaders Celtic to five points by beating Hamilton.