Danny Graham has reportedly begun arranging extra fitness sessions in order to keep his place in the Sunderland squad.
The 29-year-old struggled to make an impact after joining the North-East outfit from Swansea City in 2013.
After failing to score in his first 27 games for the Black Cats, the 28-year-old, who was sent out on loan three times, managed to influence results in the closing stages of the season under new head coach Dick Advocaat.
According to the Sunderland Echo, during the summer break, Graham has been putting in extra sessions at his local gym Club 29 Fitness, with specific focus on strength and conditioning.
Sunderland will begin the new Premier League season away to Leicester City on August 8.