The Yorkshire giants have spent the season in the top half of the Championship standings, but their poor form since Christmas has resulted in the club now sitting in 12th place in the table.
Leeds host leaders Wolverhampton Wanderers on Wednesday night, and Heckingbottom has encouraged his team to play like their careers are at stake.
The 40-year-old is quoted by the Yorkshire Evening Post as saying: "One game can change the managers thoughts, your confidence, your belief and a watching scout or a watching managers opinion of you both positively and negatively.
"So you're always doing that every day in training. I'd love everyone to understand that and really think about it every day before you come into work. That's what is at stake."
Heckingbottom has recorded five points from his first five games in charge of Leeds.