The former Swansea player will definitely miss Friday's home game with Bolton Wanderers at Hillsborough.

Next Tuesday, the Owls visit Barnsley for a big South Yorkshire derby.

Admitting to concern regarding the length of the lay-off regarding Byers, who missed a chink of the season in late autumn and early winter with a foot injury,

Moore said: "George has sustained a muscle injury and it's going to see him (not) be fit enough for the game.

"From last week, we assessed George further in terms of the extent of the injury and how long. But really (for Bolton), he won't be available.

"It's always a concern when you pick up a muscular injury at this stage of the season where there's multiple games on the horizon. You don't want to miss anybody, you want bodies back.

"So it is important we are getting bodies back as opposed to losing bodies."

Wednesday will have another enforced change from their starting line-up at Fratton Park, with Dominic Iorfa suspended, although Marvin Johnson does return from a three-match ban.

Johnson was suspended for three games after he was found guilty of ‘improper/violent conduct’ by the Football Association.

Johnson was charged over an off-the-ball incident with Ipswich Town's Wes Burns in the 2-2 draw between the two League One high-fliers at Portman Road last month.

Moore said: "Obviously, Dom is out, but we have Marvin back and these are aspects where we know we will adapt accordingly and adjust the team as we see fit.

"We may make a few adjustments, but carry on the same."

Key Sheffield Wednesday midfielder George Byers to miss Bolton Wanderers game - and a big doubt for League One derby at Barnsley FC