He wouldnt need to be a lone forward. I suspect this season that we are going to play more fluid with the front players interchanging. Depay will be coming in from the left to either support Rooney or, starting out upfront and then moving into channels to spread defenders, creating room for the likes of Di Maria, Mata, Herrera and Fellaini to exploit.
We'll know a lot more about his intended shape and formation on the tour but I think he's got Depay knowing full well he can play as a striker if needed. Especially if we are a lot more fluid and keeping the ball on the ground, rather than having a target man like Fellaini. Like I say I think he could be the next best thing to Thierry Henry in style. A few years as a winger cutting in supporting Rooney/RVP ect and then eventually start playing more as a striker.