Martin, 38, believes the sheer talent he possesses means Amo-Ameyaw's size "really doesn't matter" with the 18 year old tipped for big things.
Martin had previously admitted Amo-Ameyaw's minutes have been limited compared to Tyler Dibling due to the latter physically developing quicker
The former Tottenham starlet made his first Premier League appearance since the opening day of the season during Saturday's trip to Aston Villa.
Although Amo-Ameyaw was unable to help his side recover a point, succumbing to a 1-0 defeat, he put in the best cross of the day with his first touch.
"Sam's got a development plan the same way they all do and we spend a lot of time talking to the performance department," Martin insists.
Sam Amo-Ameyaw has made 12 senior appearances for SaintsSam Amo-Ameyaw has made 12 senior appearances for Saints (Image: PA)
"We are making sure we marry up what we require from him on the pitch specifically for him as a player and his position with what he does in the gym.
"He's an outstanding talent, very different to Tyler physically but Sam's done really well to get himself on the bench in the Premier League and to stay on there.
"I have no doubt at some point he will be a really good player for this club and he's getting better all the time, we're seeing things we really like from him.
"I have spoken to you about Tyler and the stuff that he does so well now compared to last year and Sam just needs to keep stepping up and look at his mate.
"He's capable of doing that. He's never going to be the biggest player but it really doesn't matter when you're as talented as he is.
"He needs to learn how to use what he has when he's protecting the ball sometimes and it's up to us to help him with that," added Martin.
The youngster scored the first goal of his career at Cardiff CityThe youngster scored the first goal of his career at Cardiff City (Image: PA)
"It's also about the physical demands when he comes out of position and him understanding his role and what he needs to do to help the team."
Martin was asked about Amo-Ameyaw's development after he was the only attacker left on the bench in the 5-1 defeat to Chelsea last week.
All four attacking starters were brought off - with Saints down to 10 men - while Kamaldeen Sulemana and Ben Brereton Diaz were introduced.
"Down to 10 men and in that situation, it was just about defensive work at that point, so Sam just had to be patient," Martin explained.
"We're the second youngest team in the Premier League and in a position where I'm not sure we can have too many players under 19 in the team at once."