The Northern Irishman has regularly lamented a lack of cutting edge in his side, most recently in last week's William Hill Scottish Cup fifth-round exit to St Mirren in Paisley.
Lomas is aware the controversial Griffiths, 22, knows his way to goal with 15 for the season and is likely to be the biggest threat to the Perth men.
He said: "Pat [Fenlon] has brought in good players like James McPake, Ryan McGivern, and they have Griffiths up front.
"He is a goal-scorer and determined attacker. When a player like him is playing for you you always have a chance."