Hull says scans have showed the foot injury sustained by new signing Gareth Ellis is not as bad as first feared, although he is facing a spell on the sidelines.
The England back rower, who was appointed as the Black and Whites' captain after joining them on a three-year contract from Wests Tigers, injured his foot during the warm-up for Friday night's Super League opener at Leeds.
The injury rekindled memories of the fractured foot that kept the 31-year-old former Wakefield and Leeds favourite out for three months last season but Hull say it is not a re-occurrence of the same injury.
"Ellis will visit a specialist early next week before an accurate assessment of the extent of his injury can be confirmed and how long he'll be out of action," said a Hull spokesman.
Gareth Ellis is back in Super League and will line up against the Leeds Rhinos as Hull FC take on the champions at Headingley Carnegie.
Ellis helped Leeds to Grand Final success over St Helens in 2008 and spent the last three seasons playing in the NRL with the Wests Tigers.
Mitch Achurch, Joe Vickery and Joel Moon are all set to make their Super League debuts for Rhinos on Friday evening.
All three have been named in head coach Brian McDermott's 19-man squad for the opening game of the season.
The Rhinos are only without Ben Jones-Bishop and experienced forward Kylie Leuluai through injury so McDermott is able to field a near full-strength squad.
Wing Jones-Bishop, 24, will be sidelined for six months as he is undergoing a course of treatment after being diagnosed with a pulmonary embolism in pre-season training.
Leeds might be back-to-back champions, however, McDermott is determined to improve Leeds' form on a consistent basis.
"I do not look at the things we've achieved in the two years I've been at the club," he said. "Unfortunately, I look at the two losses we've had in the last two Challenge Cup finals.
"I also look at our scratchy league form week in week out over the last two years. Those are the things I focus on."
Hull FC are expected to have no less than seven new signings on show at Headingley after Peter Gentle named his 19-man squad for the clash.
Prop Paul Johnson, second row Richard Whiting and half-back Richard Horne are all named after featuring in the 60-14 victory over York last weekend.
Forwards Danny Tickle (bicep) and Liam Watts (thumb) miss out as expected.
Leeds: Hardaker, Watkins, Moon, Hall, McGuire, Burrow, McShane, Peacock, Jones-Buchanan, Ablett, Sinfield, Ward, Delaney, Bailey, Kirke, Clarkson, Achurch, Griffin, Vickery
Hull FC: Arundel, Briscoe, Crookes, Ellis, Galea, Green, Heremaia, Holdsworth, Horne, Houghton, Johnson, Lynch, McDonnell, O'Meley, Pitts, Seymour, Westerman, Whiting, Yeaman