The G-League’s regular season was to end Friday and Knicks rookie small forward Ignas Brazdeikis would have gotten his chance, according to sources. With the Westchester Knicks out of the playoffs, April games were expected to be a showcase for the 21-year-old Canadian to show why the Knicks moved up in the second round from 55 to 47 to grab him. “That was the plan — join the team, get an opportunity,’’ an NBA source told The Post. “The Knicks were happy with his development. He kept a real positive mentality, kept his head down and was excited about the opportunity.’’