The 22-year-old striker was overshadowed by Daniel Udoh on his return to the club last season, having netted 25 goals on loan at the New Bucks Head from Burton Albion in 2017/18.
And Cowan wants Dinanga to get back to that level – as he battles fellow new-boy Aaron Williams, as well as Andre Brown, for a place in the Bucks’ starting XI.
“He comes alive when we’ve got the ball,” said Cowan after watching Dinanga score twice in Tuesday’s 3-1 win over Market Drayton Town. “We know he’s still got to work hard with things to work on.
“He’s a player that has knack scoring goals, if he gets chance he puts them away.
“He’s a massive player for us, as is Andre (Brown) and Aaron (Williams).
“They all need coaching because they can always be better. We can all get better, I ask my staff on what I can improve on.
“There’s one specific thing we want to work him on but when he gets the ball he comes alive.
“The one word I would use with Marcus is ruthless. He has a ruthless mentality.
“That is a massive positive in so many ways for us and we want to get him ruthless in other ways.”