The former Liverpool favourite says the Spaniard is better offensively than defensively.
The full endured a mixed evening on Thursday in the Europa League semi final against Villarreal as he put in a solid display before a key mistake at the death saw the Spaniards a late winner.
It was a major sucker punch for the Reds, who would have been more than happy to take a 0-0 draw back to Anfield for the second leg next week.
Moreno came in for most of the criticism for the goal, and Lawrenson says it is because he is better offensively than he is defensively.
"When the players watch that goal tomorrow, Klopp will be trying to make the point that they have to do their job," he told BBC Sport.
“If you are a left back, defend. We have a left back [Moreno] who enjoys going forward and he is better going forward than he is defensively."
Moreno’s performance will not have helped his quest to prove himself as the first choice left back in Jurgen Klopp’s side.
He is arguably among those whose first team place could be in danger this summer as the Reds gear up for a busy transfer window.
He has struggled to impress since joining under former manager Brendan Rodgers and this latest error is sure to add to the belief by some that he is not good enough and should be replaced.