The young striker is shining for the U23s this season.
Lambert said: "I was at the U23s game on Monday night and Tyrese Campbell scored two good goals. He has a bright future ahead of him if he keeps his feet on the ground. He's one I want to keep close to the first team.
"We could have let him go out on loan, but I didn't want to do that. He has a great future, but it is a big ask at such a young age. But do I think he would buckle? No I don't."