Carruthers has been heavily involved in preseason.
But asked if the Ireland under-21 midfielder would feature much this season, Lambert replied: "I don't know. He is a young lad learning a lot about the workings of the game. But he has done fine.
"He's offensive, that's his strength. There are a lot of good players in the side at the minute that he will have to try to dislodge.
"That's the nature of the game so he has to try to fight to get into the side. It's the same for every young player."
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