The 22-year-old is flourishing this season at Old Trafford, having scored 13 goals in his 14 appearances.
His form has helped propel United up to fifth, and Lingard is expecting even more from the England international over the course of this season.
Lingard told Sky Sports of Rashford: "He's been doing really well. He's so humble and down to earth and he loves to work hard, and it shows in the matches.
"He's only so young, he's only 22, and the world is his oyster at the moment.
"Football's all about enjoyment and he loves scoring goals, he loves celebrating. That's what he's there to do, he's there to score goals."