The midfielder signed a pre-contract agreement with Villa in March before joining from Eredivisie side AZ Alkmaar at the end of last season.
Lambert understands Holman might be concerned about his future but has sought to give him assurances, and said: "If there is one lad who has probably got a bit of trepidation, then it would be Brett because it wasn't me who brought him to the club. But I have spoken to him to reassure him and he will get a right fair chance."
He went on: "I don't know much about him but I have watched some of his games. He did well at Alkmaar so I don't have any worries about him on that score.
"It's not as if you are going in with a young kid. He is 28.
"As long as he works hard and tries to be successful, then he will be the same as everybody. He will get a chance."
Source: PA
Source: PA