The 23-year-old frontman took his tally for the season to 10 goals on Saturday with a match-winning FA Cup fourth round double against npower League Two side Aldershot.
Mowbray said: "Lukas gives every centre-half he plays against a real hard day.
"People forget how young he is and yet he puts his body on the line every week. It's good for him that he gets the goals for his efforts.
"Sometimes a battering ram of a centre-forward has physicality as a strength, but can expend a lot of energy.
"But Lukas' job is to score goals and on Saturday he got us the goals that won us the game."