Paul Johansson, who plays Nathan's father Dan, signed up to appear in the show's final season and returned in last week's premiere.
However, Lafferty told TV Guide that the duo's troubled relationship could begin to improve.
"In the past, Dan's presence has brought a lot of turmoil and conflict, but this year, the way he colours Nathan's life is much, much different," he said. "Nathan's actually going to need Dan a bit more this year."
Lafferty explained that a large part of Nathan's storyline will revolve around "whether or not he can forgive Dan" for killing Keith but suggested that fans will be pleased with the way the show finishes.
"Tying this relationship up between Nathan and Dan is something that was really needed for Nathan's storyline, Dan's storyline and probably the show as a whole," he said.
"This season, Dan's back in a huge way and there's very close attention paid to that relationship between father and son that either needs a total break off or mending."
One Tree Hill airs on Wednesdays at 8/7c on The CW.
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