Firmino was impressive in the recent 3-3 draw with Arsenal.
The duo have been impressive in the big games for the Reds this season, with top drawer performances against the likes of Chelsea, Manchester City and Arsenal.
However, they have struggled to do that consistently in every game, with them often going missing in matches against the so-called lesser teams.
That makes things difficult for Jurgen Klopp’s side, who rely heavily on Coutinho in particular, and Lawrenson has called for them to be more consistent with their displays.
“In many ways Firmino remains very similar to his fellow Brazilian Philippe Coutinho in that they’re both either brilliant or very ordinary,” he told the Liverpool Echo.
“It’s better for managers to have a solid player who can give you a seven out of 10 performance every week but with Firmino and Coutinho it seems to be a nine followed by a few fives and sixes.”
“I’m not sure if it’s a South American trait but at times they seriously disappear from games when you want talents of their ability to be more involved in the action.”
After his impressive display against Arsenal in midweek, Liverpool will now be hoping Firmino in particular can score on a more regular basis.
The Reds have struggled up front this season, with Christian Benteke their top scorer with seven goals to his name, but so far he has struggled to impress at Anfield.
With Daniel Sturridge also still struggling for fitness, there is a shortage up front in Klopp’s side, and he will be hoping that hole can be filled by the Brazilian in the second half of the campaign.