Can Ronaldo play a strikers'role?

He sure can. He can play anywhere in the attacking positions, left side, right side, cutting into the middle, through the middle or upfront. He wasnt effective on the wing against Pool so he finished the game playing upfront with Rootev dropping back some. So he has played as a striker. Its no problem for him. His best position is starting on the right and alternating throughout the match depening on circumstances in the match.

Yes he can.

He's already played that role for United and Portugal. In fact, when Tevez was brought off against Liverpool Fergie moved Rooney out wide and Ronaldo up front (although that was more to do with Rooney being better at defending when we were trying to hold on to a lead).

he's playng great where he is now..but....if we would be short of strikers.....of course he would be an option

Yeah i hope we don't need him up there this season, but if we did become short on strikers he'd play there no problem. Think he played up front for sporting a good few times :S

Ronaldo was signed by United as a winger. But he is classed in many stat books/sites as a striker. As to the question - yes.