Phillips missed a large chunk of the current Premier League campaign through injury and only returned to the first team fold in mid-March.
The midfielder is yet to get back to his best for the Whites, while they are going through a tough campaign, currently struggling in the drop zone.
Former Leeds star Martyn is of the view that Phillips is suffering from fatigue, as he is struggling to reach the levels that the club are accustomed to from him in the middle of the park.
Martyn feels that an extended season prior to this one, owing to his participation in the European championship with the Three Lions, coupled with his spell out due to injury and Leeds going through a rough campaign of their own, are all reasons for his dip in form.
“It has been a hard season for us and Kalvin picked up that injury”, Martyn said on BBC Radio Leeds.
“And he just looks a little bit laboured at the moment.
“He is still searching for what we saw before when he was like a Gazelle running around.
“He really covered the grass really easily.
“Now it looks a little bit harder for him to do it.
“And I think that is just the result of a very long year, last year [with an extended season as he played in the European Championship].”
Phillips has admirers in the Premier League in the shape of Manchester United and Aston Villa, and he could part ways with the Whites if they fail to stay afloat in the top flight.
