KALAMAZOO, Mich. – The Western Michigan baseball team and head coach Billy Gernon have announced the signing of transfers Jack Grunkemeyer (Northwestern), Nathan Harb (Niagara), Collin Lott (Northern State) and Casey Robertson (Henry Ford CC). The quartet joins 17 student-athletes already signed to the program who are slated to arrive at WMU in the fall of 2026 and begin suiting up for the Broncos for the 2027 season.
 
Jack Grunkemeyer • RHP • 6-3 • 215 • Batesville, Ind. • Batesville HS (Northwestern)
Grunkemeyer is set to arrive at Western Michigan after playing the first two seasons of his collegiate career at Northwestern. The righty made a total of 24 appearances for the Wildcats and struck out 29 in 46.2 innings.
 
This past season, Grunkemeyer pitched in a pair of road contests against ranked foes, taking the mound at #5 Georgia Tech and #21 Oregon. As a freshman in 2025, he led all Northwestern pitchers with 22 appearances, collected a pair of wins and earned two saves. He was a member of the Dean's List during both of his years in Evanston.
 
Ranked the No. 35 player in the state of Indiana by Perfect Game, Grunkemeyer was a four-year starter and four-time All-Conference performer for head coach Tyler Burcham at Batesville High School, where he helped lead the team to a pair of IHSAA 3A Section titles. He threw a no-hitter during his senior campaign on the way to earning District Player of the Year, 3A All-State Honorable Mention and an invite to the North-South All-Star Game. As a junior, he posted a 2.03 ERA and racked up 61 strikeouts in 38.0 innings. He also played basketball at Batesville. In the classroom, he was on the All A Honor Roll all four years and a four-year Kiwanis Scholar.
 
Nathan Harb • RHP • 5-11 • 180 • Bothell, Wash. • Inglemoor HS (Niagara)
Harb is slated to join the Broncos after spending the 2026 season at Niagara University, where he helped the team to a 27-21-1 record, 20 conference wins and a tie for second in the Metro Conference standings. He pitched in 17 games for the Purple Eagles this past spring and posted a 3.76 ERA across 26.1 innings. The righty went 3-0 and collected 21 strikeouts while limiting opposing hitters to a .255 batting average.
 
A three-year letterwinner for head coach Craig Bishop at Inglemoor High School in Kenmore, Wash., Harb began his collegiate career at Everett Community College in his home state, where he helped the program win a pair of North Region titles. Playing under head coach Keith Hessler, the right-hander collected 16 saves and three wins while posting a 2.37 ERA across 38.0 innings in his two years with the Trojans. Harb totaled 48 strikeouts in his time at Everett for a strikeout rate of 11.4 per nine innings.
 
During his second season with the Trojans in 2025, Harb held a 1.25 ERA, earned 10 saves and fanned 24 in 21.2 innings for a strikeout rate of 10.0 per nine innings. Following the campaign, the right-hander earned First Team NWAC North, Second Team All-NWAC and All-NWAC Academic Team honors.
 
Collin Lott • C • 5-10 • 190 • Oakland, Mich. • Stoney Creek HS (Northern State)
Lott is headed to Western Michigan after spending the 2026 campaign at Northern State. He started 40 games and hit .308 with a .420 on-base percentage and .504 slugging percentage. He scored 25 times and tallied nine doubles, five home runs and 25 RBIs. Defensively, Lott posted a .981 fielding percentage and threw out 19 runners trying to steal. He earned a South Dakota Army National Guard Athlete of the Week award and was named to the President's List after both the fall and spring semesters.
 
A Michigan native, Lott played for head coach Paul Diegel at Stoney Creek High School in Rochester Hills, Mich. As a senior, he hit .357 with three home runs and 23 RBIs on the way to being named First Team All-League, All-District, All-Region and All-State, and earning an invite to the MAC vs. OAA All-Star Game. Lott was an All-League and All-District selection following his junior campaign, and was also All-League as a sophomore while helping the Cougars win a regional championship. He excelled in the classroom as well, earning Academic All-Region honors in both 2023 and 2024, before being named Academic All-State in 2025.
 
Casey Robertson • INF/RHP • 6-1 • 210 • Lake Orion, Mich. • Lake Orion HS (Henry Ford CC)
Robertson is set to join the Broncos after spending the last two years at Henry Ford Community College, where he played for head coach Jake Pacholski. This past season, he hit .407 with 20 doubles, 10 home runs and 62 RBIs, while posting a 4.06 ERA and collecting five wins and seven saves in 16 appearances on the mound. Robertson was selected to the MCCAA First Team All-Eastern Conference, the All-MCCAA Team and the Region XII All-Region Team.
 
During Robertson's first season at Henry Ford, he owned a .329 average with nine doubles, five home runs and 33 RBIs. He also pitched in six games, registering a 2.08 ERA and picking up a pair of saves. He earned a Second Team All-Conference selection and helped the Hawks win the MCCAA Eastern Conference title. He also received All-MCCAA Academic Honors and graduated from Henry Ford with an associate's degree in Business.
 
Robertson graduated from Lake Orion High School, where played for head coach Andy Schramek. In his prep career, he helped the Dragons to back-to-back district championships and was also selected to the MAC vs. OAA All-Star Game.