Agree with that, the slowest midfielder we have is Gerrard, but he is just about accommodated. We keep being linked with M'Vila, who does suit the mobile destroyer/playmaker that Rogers is keen to sign up next month.
Xabi is a great player but not for the way Rodgers wants his team to play. He used to be much less mobile than Gerrard and I doubt he's any quicker now. He would be useful away from home against better teams than Spurs where we could sit back and counter with long range passes.
Mascherano on the other hand would be a brilliant signing but very unlikely unless Barca do the unthinkable and sign a decent centre-back (not Luiz then). He's perfect for a high tempo pressing game except for his occasionally reckless style of tackling.