كتب : Hatem Maher
The Egyptian midfielder, who was linked with a host of clubs in the close season including his former club Ahli, has yet to make his first appearance with the Championship (second division) side this season.
"Mohamed has not been fit enough to train with the first team squad," Southgate was quoted as saying by Sky Sports.
"He's working with the medical team in order to recover."
The 27-year-old, who joined Middlesbrough from Ahli in the summer of 2007, is playing regularly for Egypt though.
He featured in the Pharaohs' 1-0 victory at Rwanda in the World Cup qualifiers earlier this month but will not be able to play in the upcoming clash away to Zambia due to automatic suspension.
"He's had a lot of commitments with Egypt over the past few weeks," Southgate, who remained in charge of Boro despite their relegation, added.
"He needs to get fit again and back in full training and then he will be considered."