By Matthew Geagan, CBS Boston

BOSTON (CBS) — The honeymoon between Kemba Walker and the New York Knicks is over, with head coach Tom Thibodeau announcing Monday that the team is taking the point guard out of its rotation. It’s another unfortunate turn in the final stages of Walker’s career.

READ MORE: 'It Was A Nightmare,' Salem Father, Daughter Back Home After COVID Puts Both In ICU

It also highlights just how right the Celtics were to do anything and everything they could to move on from the final years of Walker’s max contract over the offseason. Sure, it cost Brad Stevens a first-round pick to get Walker off the books, but it subtracted one of the team’s many (many, many, many) issues of the past few years. With Walker, there was always a carrot dangling that maybe, just maybe, he would be a healthy and spry guard again, one that was able to impact the Celtics the way he did his first season in Boston.

But that was never going to be the case, and weight of Kemba’s health is no longer on the team’s shoulders. And the Celtics did get something in return for Walker, a pretty important set of shoulders that has been a wonderful surprise for the team in 2021.

That would be the shoulders of Al Horford, who has been rejuvenated by his second stint with the Celtics and has turned in an incredible season thus far. The 35-year-old has averaged 12.5 points off 45 percent shooting to go with 8.3 rebounds and 1.6 blocks per game. He has a double-double in eight of his 18 games played, including a 17-11 showing in Sunday night’s win over the Toronto Raptors. He’s done it all while still owning the most dashing set of eyes in the NBA.

Horford was putting up some truly insane block numbers to start the year, averaging 2.6 per game over his first 10 games of the season. So those numbers, and his numbers overall, have returned to normal a bit over the last few weeks.

But Horford’s impact on Boston goes much deeper than what he does on the score sheet. His stats are certainly a welcome addition to Boston’s frontcourt, but it’s  the availability and dependability of Horford that has the Celtics in a much better spot in 2021. Robert Williams is the big man of the present and the future, but as we know with Williams, he tends to get banged up a bit. He’s already missed a handful of games this season, which in years past, would have severely hampered Boston’s cause.

READ MORE: Market Basket 'Stole The Number 3 Position From Trader Joe's' In New Grocery Retailer Rankings

But this year, Horford has saved the day when Williams hasn’t been available. The Celtics are 3-3 without Williams this year, thanks in large part to Horford giving them some incredibly important minutes. Horford at the five has let Grant Williams play some fill-in four, and the third-year forward has given Boston some of the best shooting of his career.

And then there is the leadership that Horford provides as well. He is obviously the old man of the kid’s club that is Boston’s locker room, someone who the younger Celtics know they can rely on whenever they need a veteran’s perspective. With a first-year head coach in Ime Udoka, that is a nice added value for Boston when it comes to their veteran big man.

It stinks that it didn’t work out with Walker in Boston, and it stinks that it seems like his New York career is heading in the same direction. Walker was always a pro about his struggles with the Celtics, and his health just never let him return to the form he showed in his first few months with the team.

But Stevens was heavily criticized when he sent Walker and a first-round pick to OKC for Horford and Moses Brown (later flipped to the Mavs for Josh Richardson), his first major move as President of Basketball Ops. in Boston. The swap was seen mostly as addition by subtraction, and Horford (and his contract) was mostly seen as trade bait for later down the road.

It turns out, bringing in Horford has been huge for the Celtics on a number of different levels.

MORE NEWS: NH Bar Employee Halts 'Dangerous And Frightening Situation' By Tackling Man With Gun

This is no knock on the Knicks for signing Walker to a bargain deal. They are 11-9 on the season and currently ahead of the Celtics in the standings, so New York fans can cry “scoreboard!” all they want right now. But the Celtics had to move on from Walker, and as it turns out, they were lucky to get someone like Horford in return.