I'm sure he still has enough juice to play as a 2nd/3rd line guy, but he isn't going to outscore Stone/Ryan in that role which bumps down his ability to significantly improve the team. His legs might be shot too, so his ability to outplay them on the backcheck (Alfredsson's strength) would be limited too.
He would be an upgrade on Lazar/Chaisson, but how much of an upgrade considering he'd be limited in icetime? 4 goals over a season? more? Keep in mind, he's not playing on the PP, so any improvement on those guys would come during ES. If it was 12 points more than Lazar in a season occupying a similar roll I'd be surprised. There's a reason you can't put a guy like Spezza on the 4th line and expect 60 points from him.
The reverse side of this is that, eventually, Ottawa needs to win without Alfredsson, Neil, and Phillips. That means guys like Lazar and Stone and Puempel and Hoffman need experience. You can't get that experience if Alfredsson is eating your lunch.
Normally, I'm a big fan of veterans, but this team isn't going to win the cup. Might as well play the kids.