Not necessarily. Goalies get hot in the playoffs all the time. Holtby still only played 6 games outside of the playoffs. Look at the Halak situation (only one that comes to mind right now, but I know there are others). It's hard to bank on a hot streak from a goalie in the playoffs.

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12 Team Keeper, Keep 17, Keepers
Roster: 4C, 3RW, 3LW, 5D, 2U, 3B, 3IR, 4G (Start 2)
Stats: G(3), A(2), +/-, PIM(0.5), PPP(2), SHP(3), GWG(2), HITS(0.1), BLKS(0.2), W(3), L(-1), OTL (1), GA(-1), SV(0.2), SO(3)

C: Crosby, Tavares, Nugent-Hopkins, Johansson
LW: Hall, Parise, Silfverberg, Skinner, Conacher, Jokinen
RW: Seguin, Hossa, Wheeler, Burns, Pavelski, Yakupov
D: Doughty, Fowler, J. Johnson
G: Schneider, Hiller, Fasth, Nabokov