The Sacramento Kings do not show restraint in their play, instead operating with the intensity of a group not yet tired of the NBA’s incessant grind.Their boundless energy left the Nets gasping for air at times Tuesday night, as the Kings sprinted out to 28-point lead in the third quarter. In other moments, though, it left them vulnerable, allowing Brooklyn to storm back to claim an unlikely 123-121 win on a last-second Rondae Hollis-Jefferson layup. For the league’s fastest-paced team, it was another uneven night of work. And while many peg the Kings to eventually transform into a playoff contender, this coming summer could stall the fun.Center Willie-Cauley Stein will be a restricted free agent and Sacramento’s first-round draft pick is almost certainly headed to Boston from a trade completed in 2015, meaning there will be few avenues to meaningfully improve a roster that has yet to reach the playoffs in a difficult Western Conference.Adding forward Harrison Barnes and his $25 million player option for 2019-20 before the trade deadline made additional maneuvers more challenging.MORE: Our shifting view of KareemWhether Sacramento is able to come away from the summer a better outfit than before will depend on whether its front office has finally gotten itself together after decades of malpractice.The best-case scenario for the organization is obvious: lightning-quick point guard De’Aaron Fox and 2018 first-round pick Marvin Bagley develop into a legitimate stars, and Buddy Hield and Bogdan Bogdanovic offer consistent supplemental shooting from the wings to form a satisfactory supporting cast. Harry Giles perhaps also becomes an NBA starter, having offered glimpses of his two-way potential.Such an outlook was visible most of Tuesday night, starting with a 38-point first quarter in which eight different players scored. The Kings passed the 100-point mark with 2:08 left in the third quarter. Fox finished with 22 points and nine assists. Bagley had 28 points and seven rebounds.But you don’t need to squint to see the worst-case scenario with this franchise unfold. It was right there as the Kings allowed D’Angelo Russell to ignite in the fourth quarter to torch what had been a stellar performance. It’s possible the current crop of up-tempo youngsters never develops the defensive acumen necessary to truly compete in the brutal Western Conference, and the team’s cap space and draft capital ultimately proves insufficient to bolster a group seemingly one piece away from clicking.As exciting as the Kings have been for parts of the season and even parts of individual games, the lingering concern is difficult to completely stuff away.The key for Sacramento, at least in the short term, may be unlocking the full talent of a player Golden State and Dallas failed to open up. Barnes, who has not come close to living up to the hefty salary Dallas gave him three summers ago, could be boosted by a better fit with the Kings.At 26, there is still flickering hope he can salvage his career and become at least a positive contributor. In a small, 16-game sample with Sacramento this season, he has posted his best net rating since he was with the Warriors. Barnes has also improved his shooting numbers. Crucially, he has done those things with a usage rate down significantly from when he was in Dallas, perhaps signaling he is best suited as a complementary player rather than a key offensive cog. His best stint in the NBA, of course, came when he was part of a young, ascending Golden State team.For the Kings to make the playoffs next season, Barnes won’t need to be a first or second scoring option. That’s what Fox, Hield, Bogdanovic and Bagley are there for. What he will have to be is an efficient shooter who can space the floor on offense while defending at a high level.If Barnes can’t do that, there might not be many other avenues for Sacramento to find answers.