After pulling off the thrilling TIE fighter chase in the last episode he directed, season 2’s “Chapter 12: The Siege,” Weathers directs a Jedi massacre, an airborne rescue mission, and Grogu’s first fight scene in “The Foundling.”

Source: https://gamerant.com/the-mandalorian-season-3-episode-4-review/

Being in Luke’s presence for a short time wouldn’t have justified the growth of Grogu’s power, and his return to Din made it clear that they had been training for a while.

Source: https://screenrant.com/star-wars-timeline-after-return-jedi-mandalorian-sequel-trilogy/

Season 3 is expected to chronicle Din and Grogu’s next space adventure, with Din trying to regain his honor by coming back home to the war-torn planet of Mandalore.

Source: https://www.cbr.com/the-mandalorian-season-4-filming-fall-2023-star-wars/

The Book of Boba Fett added to that intrigue with a glimpse of Grogu’s brief training arc under Luke Skywalker.

Source: https://gamerant.com/star-wars-the-mandalorian-force-powers-grogu/