Gyllenborg has a large frame and has an athletic build at 6-foot-5, 200 pounds. He is a right-handed hitting outfield prospect and right-handed pitcher out of Rockhurst HS in Kansas City, MO. He shows good foot speed for this size while running a 6.99 second 60. At the plate, 85 mph exit velocity, athletic stance, quiet load, in line stride, hands work, barrel control, remains balanced throughout swing, hard contact at the plate, showed ability to work inside the baseball, lift and pop to left field during round. Defensively, good actions in the outfield, works behind the baseball, long clean arm action, high three-quarter release, some carry to throws, mostly accurate with a positional velo of 81 mph at the event. On the mound, long limbs and projectable frame, athletic delivery, fluid movements, repeats with some effort, loose arm action, three-quarter release. Fastball is 79-83 mph at the event, some arm side run, around the zone, curveball is 69-72 mph at the event, 11-to-5 shape, late action, thrown for strikes.

6/5/18 - Gyllenborg is a long and lean 6-foot-3 170-pound right-handed hitting outfielder and right-handed pitcher in Missouri’s 2021 class.  He ran a 7.09 60 and has a 4.56 home to first time.  He has an 85 mph exit velocity. At the plate, balanced stance with smooth pre-pitch rhythm, toe tap to inline stride, hits with leverage in lower half, hard gap to gap line drives, quick bat speed level through the zone.  In the outfield, 81 mph positional velocity, high three quarters arm slot, loose arm action, clean exchange, works through the ball, still room to fill out physically. On the mound, over the top release, slight hip rotation at balance point, long take away from glove with loose arm action, in line stride with shoulders remaining level, fastball at 77-81 mph, flashes arm side run, 12-to-6 breaking ball, gradual break, down in zone, 65-66 mph, throws high number of strikes repeating delivery.

7/5/17 - Gyllenborg is a lean and long 6-foot-2 150-pound right-handed hitting outfielder and right-handed pitcher in Missouri’s 2021 class.  He ran a 7.50 60 and has an exit velocity of 79 mph. At the plate, balanced stance, hands walk away from stride, stays in line, loose hands, consistent hard contact to middle of the cage during batting practice, stays on ball after contact.  In the outfield, 76 mph positional velo, over the top release, crow hop, momentum through the catch, hands and feet work together, smooth actions. On the mound, Gyllenborg is long limbed and lean, arm action and build would suggest continued increases, over the top release, fluid tempo in delivery, commands zone with fastball, release out front, simple delivery, repeats, athletic finish, fastball at 73-75 mph, breaking ball has 12-to-6 action, gradual, misses on bottom of zone, change up has slight arm side release, throws with near fastball arm speed, throws for strike, mostly 66-68 mph.