3 Players from the Past 10 Years Borussia Dortmund Should Not Have Sold

A club that has never been among Europe's top handful of rich sides, Borussia Dortmund have had somewhat of a revolving door of star players in recent years.

Shortly after winning the Bundesliga in 2011 and 2012, Nuri Sahin and Shinji Kagawa, respectively, were sold and later replaced by Ilkay Gundogan and Marco Reus.

Mario Gotze left the club in 2013, and Robert Lewandowski in 2014, with the pair replaced by Henrikh Mkhitaryan and Pierre-Emerick Aubameyang, respectively.

Now Gundogan and Mkhitaryan have left this summer—along with Mats Hummels—and the club will look to figure out the best possible replacements for each.

Generally speaking, Dortmund have done well with little in terms of financial resources. But every club makes mistakes in the transfer market, sometimes not doing enough to hold on to a player or giving up on a talent too soon.

Click "Begin Slideshow" to see Bleacher Report's list of the three players in the last decade whom Dortmund should have done more to keep, arranged in alphabetical order by surname.

Mario Gotze

Claude Paris/Associated Press

This slide comes with a disclaimer: Dortmund had no choice in their sale of Mario Gotze to Bayern Munich in the summer of 2013. The Bavarians negotiated a contract with the player that he accepted, and they agreed to pay BVB the amount of money specified in his contract to release him from his deal with the club.

With that having been said, Dortmund's mistake was in their contract negotiations. It was difficult, to say the least: In the spring of 2012, they were on their way to a second consecutive Bundesliga win as well as their first Bundesliga/DFB-Pokal double.

By that point, they were making a name for themselves in the international press and from clubs interested in signing their best players. They had managed to convince many of their stars to sign long-term extensions, but Gotze—the club's most valuable asset—would only do so with the insertion of a release clause.

Dortmund ought to have held firmer in negotiations. Maybe they could have avoided the release clause in exchange for paying a higher salary. Or at least making the clause higher might have warded off Bayern, the last club BVB would want to sell to.

In 2012, however, Gotze penned a new contract valid until 2016. He'd be gone in a year, with Bayern having activated his €37 million release clause. The rest is history.

Kevin Kampl

Martin Meissner/Associated Press

Kevin Kampl joined Dortmund in January 2015 as a bit of a panic buy, with the Ruhr club stuck at the bottom of the Bundesliga table and at the lowest point of their recent history. It was a dark time, and the Slovenia international's capture from RB Salzburg seemed a good one.

Kampl's pace and seemingly endless stamina appeared to make him a great fit in Jurgen Klopp's system.

In a sense, he could play the role Kevin Grosskreutz did in the early 2010s. The versatile midfielder came not only as a workhorse, however, he was also a great playmaker. He was always clever on the ball, a great dribbler and reliable creator of goals who had given an impressive 18 assists in the previous Austrian Bundesliga campaign.

Yet even Kampl's natural quality could not shine in Dortmund's then-struggling side. He was sold to Bayer Leverkusen after just half a season at Signal Iduna Park. It was, frankly, far too soon.

Kampl turned things around brilliantly at Leverkusen last season, teaming up with his boss from Salzburg, Roger Schmidt. The trainer moved him into a central-midfield role, where he quickly made a name for himself. It was surely with at least a little credit to Kampl's progress that the Werkself opted to sell Christoph Kramer, a coveted player in his own right.

All in all, it seems BVB sold Kampl too early. With a few months under Thomas Tuchel's tutelage, he might have turned into a great player at Dortmund.

Tomas Rosicky

FABIAN BIMMER/Associated Press

It may seem like centuries ago, but Tomas Rosicky was a Dortmund player in 2005-06 before leaving for Arsenal.

It was a tough time in BVB's history, with the club struggling financially and having finished seventh in the Bundesliga table and outside the top five for a third consecutive season.

Perhaps there may not have been any other financially viable way than to let Rosicky go. But as with Gotze, a piece of Dortmund's soul left with the departure of their "Little Mozart."

The following season, Stuttgart won the Bundesliga with 70 points, with Bayern finishing a distant fourth.

Dortmund perhaps could have contended for the title, or at least a top-three finish in 2006-07 with Rosicky a part of their squad, but the playmaker had already left for Arsenal for (per Transfermarkt) just €10 million. It was a net loss for BVB, and coming for a player who'd meant so much to them, it was extremely disappointing.

It may be true that Rosicky spent much of his post-BVB career injured, but things might have been different for him and for Dortmund had he never left for the Premier League.