After the Boston Celtics' season came to an end at the hands of the Cleveland Cavaliers in the Eastern Conference Finals, center Al Horford believes his team has a lot of work to do in catching up to their competition.

Following Boston's Game 5 loss to the Cavs, Horford didn't shy away from where he sees things standing in the East.

"We see that the team to get past is Cleveland, and right now we're not there," he said, per ESPN's Chris Forsberg. "I'm proud of our group. It felt like we grew as the year went on. Not the way we wanted to finish, but we came a long ways from the beginning of the year, came together. We still have to keep growing as a group and getting better."

The Cavaliers have been the kings of the Eastern Conference since LeBron James returned. This marks their third straight trip to the NBA Finals and a chance at a second consecutive title. 

The Celtics were able to steal one game from Cleveland, but their four losses in the series were by an average of 25.8 points. 

Despite the lackluster end to their season, the Celtics are moving in the right direction. They led the East with 53 wins during the regular season, own the top pick in June's draft and have $19 million in projected cap space to sign a marquee free agent, per RealGM.com. 

James' presence will make the Cavaliers favorites in the East until another team knocks them off. The Celtics weren't able to get there this year, though they have the potential to close the gap quickly.