I think he represents an interesting opportunity for Rafa to showcase his ability to coach a player on an individual basis. He can improve all the defenders we sign because that's as much about working as part of a unit as anything. He's turned players like Torres and Vicente in to stars but it's arguable that they had all the tools to begin with. It'll be interesting with Riera, because the guy has obvious talents, but equally obvious draw backs. He's quicker than most of our players, but he's not anywhere near lightning. In terms of wingers - your Robben's, Ronaldo's or even Wright-Phillips' - he's slow by comparison. It'll be interesting to see if Rafa can do what alot of other top managers seem to be able to do and get the guy playing consistently to his strengths whilst setting up the team to cover up his weaknesses. Mourinho did it with Lampard, Wenger with Pires, Ferguson with countless players. I don't think Rafa's really done it with an attacker yet, at least not one that comes to mind immediately at Liverpool.
If he can do that then hopefully it'll be the end of our search for a decent wide player that's lasted nearly 10 years.