After making it all the way to the NBA Finals the year prior, the Boston Celtics entered the 2022-23 campaign with one central goal, and that was to make it back to the NBA Finals and win it.

But fast forward to the current day, and it's evident that the Celtics fell short of these championship expectations. The Celtics did put together a comeback for the ages in the Eastern Conference Finals and rallied all of the way back from a 3-0 deficit to force a Game 7, but the team laid an egg in Game 7 and lost the series. Ultimately, Boston's historic comeback was all for naught.

So, the Celtics' front office decided to make a major trade. In late June, the Boston Celtics completed a blockbuster three-team trade with the Washington Wizards and the Memphis Grizzlies. The Celtics received star big man Kristaps Porzingis, the 25th pick in the 2023 draft and a 2024 first-round pick. The Wizards received point guard Tyus Jones, Danilo Gallinari, Mike Muscala, and the 35th pick in the 2023 NBA Draft, and the Grizzlies got Marcus Smart.

Porzingis is the Celtics' most notable off-season acquisition, but he isn't their only off-season acquisition. They also signed former Pacers forward Oshae Brissett and former Raptors guard Dalano Banton in free agency. It's puzzling as to why the Celtics haven't made any more signings in free agency, though, considering they are short on players with one very important skill. With all of that said, let's take a look at one big mistake that the Boston Celtics made in NBA free agency:

1 big mistake by Celtics in 2023 NBA free agency

Not adding a proven playmaking guard to the roster

Giving up Celtics fan favorite Marcus Smart in the Kristaps Porzingis deal — who spent the first nine seasons of his pro career with the franchise — was certainly tough to swallow for many Celtics fans. The deal made sense from a basketball perspective, though, as the Celtics not only received the best player in the deal, but they also netted not one but two first-round picks from the three-team trade. But the deal wasn't without its downsides, too, as the Celtics traded away the best playmaker on their team in Smart.

Smart put together the best playmaking season of his pro career in the 2022-23 campaign. He dished out a career-high 6.3 assists per game with the Celtics, the highest assists average on the team. And Smart's assists per game average becomes even more impressive when compared to the league as a whole, as he had the 24th-highest assist average of any qualified player in the NBA this season.

Considering Smart is now a Memphis Grizzly, the Celtics would be wise to add a proven playmaking guard to their roster via free agency. The free-agent market is a bit dried up at this point, but one name who would make sense as a target is Denver Nuggets point guard Ish Smith. Smith didn't play a whole lot with the Nuggets this season but averaged 5.2 assists per game as a backup point guard with the Washington Wizards during the tail end of the 2021-22 season.

At this juncture, only time will tell if the Boston Celtics will stand pat with their current roster or decide to add more players via free agency. But what's already abundantly clear is that the Celtics should have aggressively pursued a proven playmaking guard early on in free agency.