MILWAUKEE -- After jumping out to a 2-0 lead in their first-round series with the Milwaukee Bucks, the Boston Celtics will head back home for Game 5 with things all knotted up at 2-2 following a heartbreaking 104-102 loss in Game 4. But there is no reason for despair. This was just another building block for a Celtics team primed for the future.

Down by 20 with 7:37 left in the third quarter, the Celtics seemed destined for another humiliating loss at the Bradley Center. But unlike in Game 3, when they lost by 24, the Celtics battled all the way back, even taking the lead in the closing minute of the fourth quarter. But with 5.1 seconds remaining, Giannis Antetokounmpo extended his lanky arm to tip in a Malcolm Brogdon miss and give the Bucks a 104-102 lead. It would prove to be the game-winner, as Marcus Morris' potential game-tying fadeaway from the baseline clanked off the rim at the buzzer.

It was a devastating loss in the short term but any short-term goals for the Celtics this season went out the window five minutes into opening night when Gordon Hayward's ankle snapped in half. Yes, they rattled off the 16-game winning streak, but everyone knew this team wasn't a title contender without Hayward (they probably weren't even with him, but you never know), and the season-ending surgery for Kyrie Irving simply sealed that fate.

But that in no way means the regular season was a waste, and neither is this trip to the playoffs. Every single minute in the postseason is a learning experience, and for a team with as many young players as the Celtics, these type of games are invaluable.

No ad available

"This was another learning experience for our group," Al Horford said in the locker room after the loss. "I felt in the second half we were much better, more engaged in the things we needed to do ... We're learning as a group."

There is simply nothing that can prepare a player for the pressure of having to execute on both ends in the final few minutes of a close playoff game on the road than actually having to do it. And now, these young Celtics have done that. They made some mistakes, and didn't close out the game, but as Horford put it, "those are the growing pains."

Moving forward, not only in this series, but in the years to come, the Celtics will be better off for having played in games like Game 4. They learned important lessons -- the game "showed us the type of intensity we need to play at for 48 minutes," Jayson Tatum said following the loss -- and even in defeat should have grown in confidence with the way they played after the break.

No ad available

Tatum and Jaylen Brown were both terrific in the second half as the Celtics made their comeback, scoring 37 points combined on 14 of 22 shooting from the field. Terry Rozier hit two big 3-pointers after brutal performances in Game 3 and the first half of Game 4. And even Semi Ojeleye played an important role, as he put in some impressive work on the defensive end.

All of that builds, and all of it -- even losing the game -- will help make the Celtics better in the long run.

"Playing on the road, being able to stay poised during certain situations, executing," those are the lessons Horford said this game will teach his young teammates. "We're battling, we're playing hard, but it's not good enough to just play hard. This is why playoffs are so challenging. But I think it's good for our group."

No ad available

With Hayward and Irving both expected to be ready for next season, and deep playoff runs likely in the Celtics future, it's not hard to imagine those hard-learned lessons paying off.