Leeds United head coach Marcelo Bielsa has described defender Gaetano Berardi's injury as "not a simple one" and says there is no time frame yet on his return to the Whites line-up.
The 30-year-old limped off during Wednesday's 2-0 victory over Ipswich Town at Elland Road after just 25 minutes and was making only his second start after returning from a separate issue that had kept him sidelined for a number of weeks.
Bielsa, who was speaking ahead of Saturday's clash with Nottingham Forest, admitted that the injury wasn't an easy one to manage as he gave an update over those who were racing to be fit for United this weekend.
"Gaetano Berardi has an injury which is not a simple one," Bielsa said.
"You sometimes have injuries provoked by external pressure - a hyper extension. He received an external pressure on the corner [of his hamstring] and he had to extend his muscle more than he could bare it.
"Barry Douglas will play Monday with the under-23s and he will be available after that."
Asked about the length of time Leeds could expect to be without the right-back Bielsa conceded that there was no specific return date as yet simply stating: "It won’t be a short absence."
The Argentine also faces a dilemma at left-back having opted to play Gjanni Alioski in defence on Wednesday evening but admitted that it wasn't likely to be the same starting eleven.
"I don’t think I’ll play the same players in the same positions tomorrow (against Ipswich) at least not at the beginning," Bielsa revealed. "I haven’t taken my decision yet but probably Ezgjan Alioski will play as a winger."
Asked if Adam Forshaw or Tom Pearce may be close to being handed a start after solid performances against Town in midweek, Bielsa replied: "We have a small group and all the players are close to being the starters."
Centre-back Pontus Jansson is expected to be included in the Whites match day squad following his one-game ban for comments made about referee Jeremy Simpson following the 1-1 draw with Brentford last month.
Striker Kemar Roofe is also likely to feature despite the impending birth of his second child with his partner due to give birth over the next week.