Newcastle United manager Eddie Howe has admitted that he is "not 100% sure" if Lewis Hall will join the club permanently from Chelsea next summer.
The 19-year-old, a boyhood Newcastle fan, joined the Magpies on a season-long loan deal in August which allegedly includes an obligation to buy for an initial £28m plus £7m in add-ons.
The terms agreed in Hall's deal include performance-related criteria which must be met if the versatile wideman is to sign for Newcastle on a permanent basis.
Hall has played for just 234 minutes across six appearances under Howe so far this season, including four starts, although he was taken off at half time in three of those starts.
A lack of regular first-team football has led to speculation over Hall's future, and Howe remained coy when discussing the matter at a press conference on Friday.
Asked about the details of Hall's deal and whether he expects the teenager to join Newcastle permanently, Howe said: "You're probably asking the wrong man, I'm not 100% sure."
"Lewis is a really talented player and has huge technical qualities," Howe added. "He is creative and has a very good final delivery. He is a really good attacking full back.
"He's got certain things to learn defensively which we are working on with him. But he's a young age and recently converted to left back. He may need a little time to get that defensive solidity that we're looking for."
Asked who will make the final decision on Hall's future, Howe said: "It's not mine. He's here now. He's a Newcastle player. I think there's certain criteria he has to meet."
Hall is available for selection for Newcastle's Premier League clash against Fulham at St James' Park on Saturday, but a start is seemingly unlikely for the youngster now that Dan Burn has returned from injury.
In the absence of Burn and Matt Targett, ex-Chelsea youngster Valentino Livramento has been operating at left-back in recent weeks, but the 21-year-old will likely switch to his favoured right-back position this weekend as Kieran Trippier will serve a one-match suspension due to an accumulation of yellow cards.
Hall is also capable of playing on the left wing and he could be considered for a start in an attacking role on Saturday, as Howe has confirmed that Anthony Gordon is doubtful with a possible hamstring problem.
The Magpies boss has delivered a mixed injury update on his first-team squad, who currently sit seventh in the Premier League table and enter Saturday's match with Fulham on the back of three successive defeats in all competitions. body check tags ::
