Will LaRue and Riley Pletcher are outfielders and Matt Kent is a right-handed pitcher.
Pletcher is an incoming freshman from Washington state, where he was a .323 hitter at Puyallup High School.
LaRue started 60 games as a sophomore for the Xavier Musketeers and ranked 13th in NCAA Div. 1 baseball with 31 stolen bases in 36 attempts.
Six-foot-six hurler Kent went 2-1 in eight starts and 13 appearances as an Xavier freshman with a 3.20 ERA.
The HarbourCats, who made the post-season for the first time last season, open the 2017 WCL season on June 1 in Port Angeles against the Lefties. The home opener is June 5 at Royal Athletic Park against the Wenatchee AppleSox.