Toronto FC head coach Greg Vanney is set to move captain Michael Bradley into a more advanced role.

Star striker Jozy Altidore, who has netted five goals so far this season, is set to miss up to five weeks with a hamstring injury meaning defensive midfielder Bradley is likely to be pushed forward into a more attacking position.

"Certainly, at the moment, playing in that role allows me to have a little bit more freedom in terms of moving around, attacking but still defending," Bradley said ahead of the weekend's clash with Portland Timbers.

"But, I'm not going to be a guy in that spot who's just waiting and walking around as things go on. I can give us a little bit of energy and power and the ability to still move forward but come back and help us defend in certain moments.

"I'm not always so worried about the role or the position as much as stepping on the field and competing as hard as I can to help us be successful."