The Leeds boss was speaking after his side's 3-0 win at Huddersfield Town.
Indeed, the Scot says he has been told the club are building for the long run - and that includes Byram.
Evans praised the 22-year-old's professionalism and says he has to believe the youngster is at Leeds for some time to come.
Speaking to BBC Radio Leeds, Steve Evans has said he's confident of securing 'two or three new lads':
"If I believe what I'm being told, I'm being told there’s a long term future for me and I'm building something. Sam is fantastic young man - he’s professional and talented - but I have to believe he is here for the long term.
"We have young players here but one thing they all have in common is a fantastic passion for this club."
Everything appears to be going right for the Scot just over a week after the clouds hanging over Elland Road were very dark indeed.
Blackburn Rovers embarrassed Leeds United with a 2-0 win in Yorkshire and Massimo Cellino declared his intention to sell the club.
A week later, though, and Cellino is back to 'demanding respect' and telling everyone what's what. More importantly, Leeds are winning. Back-to-back victories had become unheard of for the Whites and yet Evans has delivered some sort of momentum just five games into his United tenure.
Keeping Byram will no doubt provide a big long-term boost for the Yorkshire club but, for now, they are winning even without him!