Worse case scenario is that he blows it, gets more experience, and can learn from his mistakes in the offseason. Plus we get a better read of what he is capable of.
Shell's last 13 appearances:
W L G GS CG SHO GF SV IP H R ER BB SO HR ERA BF HBP WP BK Pit Str GmSc BA OBP SLG OPS IR IS 2B 3B SB CS
+--+--+---+---+--+---+--+--+-----+---+---+---+---+---+--+------+----+---+--+--+----+----+----+-----+-----+-----+-----+---+--+--+--+---+--+
1 1 13 0 0 0 2 0 13 8 3 2 5 11 2 1.38 53 1 0 0 217 126 .174 .264 .348 .612 7 3 2 0 2 0
Nothing wrong w/ those numbers.