Will probably be neck and neck as they've been playing on the same line for the most part and, at least recently, the same PP unit as well.
If forced to choose, however, I'd go with Huberdeau. Despite my statement above, it seems that, for one reason or another, he seen just slightly more TOI over the last several games than Mueller (though I admittedly have no idea if it's because he's getting just a little more PP time, is killing penalties every so often, taking a double-shift here and there, getting bumped up a line for a few shifts during the game or whatever).
14 Team H2H Dynasty League (14 keepers, no farm)
Weekly Starts (3C, 5W, 5D, 1Util, 2G)
G, A, PPP, SOG, BS, +/-, GAA, W+OTL, SV%
C: MacKinnon/Eichel/Kopitar//Pinto/Wright
W: Ovechkin/Toffoli/Necas/Giroux/E.Kane/K.Johnson(IR)/Schmaltz/Bjorkstrand/Drouin
D: Dobson/Trouba(IR)/Mintyukov/Gostisbehere/Martinez/Edvinsson/York/Gudas(IR)/Tanev
G: Saros/Demko(IR)/Askarov/DeSmith