Roberts, 18, is expected to feature tonight at Deepdale Stadium as Brighton look to advance to the fourth round against Alex Neil's Championship outfit.
Roberts produced an accomplished display as a second half substitute in the previous round against Portsmouth, where Albion advanced thanks to a 4-0 triumph.
He also made a goalscoring first team debut in this competition last season when he headed home from a corner during the 3-1 loss to Aston Villa at the Amex Stadium.
The teenager from Brighton has advanced through Brighton academy into the first team and has also gained 20 caps at England youth level.
Roberts is in the final year of his contract and earlier this week Leeds tested Brighton's resolve with a second bid of £800,000.
It's the second Albion defender Leeds have tried to sign this summer after three unsuccessful attempts to prise Ben White away.
RB Leipzig, Derby County and Brentford are all said to be closely monitoring the situation with Roberts.
Brighton however do not want to lose the youngster who they feel is capable of breaking into the first-team at Premier League level.
Head coach Graham Potter said, “He’s quite a quiet guy. He believes in himself a lot. He’s self-confident but knows he has still got some work to do in terms of how he is developing.
“That’s just normal because of his age but he’s ambitious, he’s confident and he wants to play.
“He has trained with us for a long time now and I’m looking forward to helping him take the next step, which is to be on the pitch for us and play games.
“It’s obviously not so easy. We have got some good competition in that position. He’s a young player we believe in.”
The rise of Roberts has drawn comparisons with Albion skipper Lewis Dunk who is also from Brighton and rose through the ranks to shine in the first team.
“I think they are completely different characters," Potter said. “He’s young and I’m sure when Dunky was that age he will probably say there were some things he could do better on the pitch.
“That’s the learning process we’ve got to help him do, to help Haydon get to that next level."
Roberts' favoured position is centre back but he can also play left back and even as a defensive midfielder.
"I think he's a centre-back, he sees himself as a centre-back," said Potter.
"Probably his best position would be left of a three at the moment, but he's really strong, physical, can defend in the wide areas well, and then he'll have to use his body to compensate for his physical stature in terms of height.
"But I don't see that being a problem for him. It's just more his positioning and decision-making and defending in a unit, which are things I think he will get better at as he gets more experienced."
Preston North End possible starting lineup: Rudd; Fisher, Bauer, Huntington, Rafferty; Gallagher, Bayliss; Sinclair, Potts, Harrop; Stockley
Brighton possible starting lineup: Steele, Veltman, Roberts, Burn, Bernardo; Mac Allister, Molumby, Propper, Gross, Jahanbakhsh, Gyökeres