HERITIER Lumumba is likely to play in a variety of roles at Melbourne including through the midfield, Demons coach Paul Roos says.

Lumumba, who crossed from Collingwood at the end of last season and was this week added to Melbourne's leadership group, made a name for himself as a running defender in his days as a Magpie.

He also spent time on the wing during his 199 games at the Pies, and looks likely to add more midfield time to his repertoire in his first year as a Demon.

"I think [he'll play] a combination of both [in the backline and the middle]," Roos said, as part of AFL Media's #AskTheCoach series.

"He has been working with the midfield group and the defensive group.

"Certainly his size around the stoppages is a big advantage, but also his run off half-back is something that we will look forward to him adding to our football club."

The Demons added Lumumba and Carlton speedster Jeff Garlett during the NAB AFL Trade period as well as young Greater Western Sydney defender Sam Frost.

Roos said the aim for this season was to improve the "balance" between being a good defensive team – which did improve in 2014 – and being more attacking.

He believed the off-season additions would help them achieve that objective.

"There is no doubt we identified speed and run as a priority in the trade period, and to pick up Lumumba and Garlett was a real positive for where we want to head as a football team."

Expand the comments below to view all of Roos' replies.