Daniel Nestor and doubles partner Nenad ZImonjic split again

This is the time of the season when the doubles specialists begin playing musical chairs, jostling for position and working on their pairings for 2015.

And once again, 42-year-old Canadian Daniel Nestor is part of it.

Last week, partner Nenad Zimonjic of Serbia announced on Twitter that he would be teaming up with Nestor's Davis Cup partner, Vasek Pospisil, at the upcoming event in Basel, Switzerland. A slight red flag, to be sure.

Sunday, Zimonjic announced on Twitter that he would play the Paris Masters 1000 with Kevin Anderson of South Africa, and that his last tournament with Nestor would be the World Tour Finals in London. A couple of days earlier, it was reported by the Times of India that Nestor would be Rohan Bopanna's partner for 2015.

In 2015, Zimonjic will team up once again with Frenchman Michael Llodra, who was the player Zimonjic originally left Nestor for towards the end of the 2010 season.

The news comes four years to the very day that Zimonjic dumped Nestor for Llodra four years ago, also during the Shanghai event. Here's what we wrote about it then.

Here's what Nestor said back then, adding that he had also been thinking about making a change and that Zimonjic merely beat him to it.

"We’ve had a lot of inconsistency in our game this season, we’ve had some great wins but also some early losses. Nenad’s also been struggling for quite some time with his elbow. I always thought we could turn it around this season, I was optimistic. But I had in the back of my mind that this could end sometime ... It was not tough at all to get the news … He might have mentioned it earlier, like at the U.S. Open, but Nenad said the decision only came when he was at home in Belgrade after the Open."

This time, Zimonjic's announcement came after Nestor and Zimonjic lost their first match in Beijing to Fabio Fognini and Leonardo Mayer and their first match in Shanghai to Lukas Rosol and Mikhail Youzhny. Not good losses, to be sure.

The second go-around for Nestor and Zimonjic this season was good, hardly great. They had a great stretch during the leadup to the French Open, defeating the No. 1 Bryan brothers in back-to-back Masters 1000 events in Rome in Madrid. But their Grand Slam results went like this: semis, quarter, quarters, third round.

Nestor has been on both sides of the doubles divorce. In late 2007, he dumped Mark Knowles, his partner of 12 years, to play with the younger, bigger-serving Zimonjic.

It was a far more acrimonious breakup than Nestor's splits with Zimonjic; Knowles, to this day, hasn't fully and truly turned the page on it. Nestor started playing with ZImonjic right after the U.S. Open that season. Then, Nestor and Knowles reunited for the year-end championships (then called the Tennis Masters Cup and played in Shanghai) – and won the thing, even though they looked on court as though they wanted to be anywhere else.

Zimonjic and Nestor won five titles in 2008, nine in 2009 and seven in 2010, including the year-end championships. Despite announcing their split in October, they continued through to the end of the 2010 season. They defeated Mahesh Bhupathi and Max Mirnyi in that year-end final – and Mirnyi ended up being Nestor's new partner for 2011.

The new pair won the French Open and the World Tour Finals together that year. Meanwhile, Zimonjic and Llodra, both fairly feisty, dramatic, shotmaking characters, seemed to have some chemistry problems. The best they could do in 2011 in the majors were semi-finals at the French Open and Wimbledon. Both, in theory, needed a calmer, more consistent partner – a Nestor, if you will. The two teams met six times in the last five months of the season, going 3-3 – all tense, tight affairs.

This time around, with Llodra officially retired from singles after the U.S. Open and fully focused on doubles, it might be different. Maybe. At any rate, it will add some spice to the doubles side for 2015.

Nestor and Bopanna played together for the first time ever at the small event in Winston-Salem this summer, losing in the first round to Colombia's Robert Farah and Juan Sebastian Cabal.

The doubles merry-go-round is never dull.