Few fans of Borussia Dortmund would have imagined their club made the best signing in years on June 8, 2015. On that date, the Black and Yellows unceremoniously announced the capture of Julian Weigl from 1860 Munich. The club's official website cited sporting director Michael Zorc saying that "Weigl is a future prospect for central midfield who we really believe has the potential to develop."

One line from an official on the player, who himself wasn't available for a quote, seeing as he was with Germany's under-20 national team in New Zealand at the time, that was it. Per Transfermarkt.de (link in German), he cost the Ruhr side all of €2.5 million. Talk about an afterthought.

Most expected the then-19-year-old to jump between the bench and the stands in Thomas Tuchel's first season as head coach, perhaps even getting some playing time for the club's under-23 outfit in the fourth division. 

Weigl was more famous for becoming the youngest captain in 1860's history at 18 years of age than anything he did on the pitch. He lost the armband after a few weeks following an incident involving him and a number of team-mates talking negatively about the club on a taxi ride, per local paper Abendzeitung (link in German)—the driver, of course, was a diehard fan of the Lions—and that overshadowed his season in the 2. Bundesliga.

Even though he turned heads with a number of good performances during the under-20 FIFA World Cup, no one could've foreseen Weigl becoming a starter right at the beginning of the season.

It didn't stop there, of course. Throughout the campaign, the 20-year-old was one of a few virtually undroppable players for Tuchel. Appearing in 51 of the club's 56 matches across all competitions, Weigl played the fourth-most minutes of all Dortmund players, per Transfermarkt, trailing only stars Henrikh Mkhitaryan, Mats Hummels and Pierre-Emerick Aubameyang.

He earned every minute he got with an astounding level of maturity and consistency. A perfect fit for Tuchel's playing style that prioritises ball retention and position play, Weigl's qualities as a passer and intelligent positioning made him one of the club's best players of the campaign.

Never flustered under pressure, Dortmund's No. 33 completed an incredible 92 per cent of his passes in the Bundesliga, per Squawka.com.

Perhaps the most impressive sign of his quality was that he got himself out of a bit of a hole around the winter break. His worst matches came in that span from late November to February, so it's not a stretch to assume he hit a rookie wall. To get out of that slump and to then play his best football for the club in the final months of the season shows just how special Weigl is.

His performances have earned the midfielder a number of accolades at the conclusion of the season.

Raphael Honigstein called him the best signing of the year in a piece for ESPN FC: "No other club in Europe's top five leagues will have done a better deal than Dortmund last summer. Weigl has played with a maturity well beyond his years in Thomas Tuchel's team, setting the pace, breaking up opposition moves and starting attacks with a quiet, understated elegance."

Per a vote by his peers in sport magazine kicker (link in German), Weigl was the Bundesliga's shooting star of the season, ahead of impressive young performers such as Bayer Leverkusen's Julian Brandt, Schalke's Leroy Sane or Bayern Munich's Joshua Kimmich.

Perhaps most importantly for Weigl, he received a call-up to the preliminary 27-man squad for the UEFA European Football Championship this summer. Even though it seems unlikely that he'll make the final squad unless there's an injury in central midfield—his lack of positional versatility is an obstacle in comparison to Kimmich, Sebastian Rudy and others—his first trip to the national team has to be the best reward for an incredible rookie campaign.

Lars Pollmann is a Featured Columnist writing on Borussia Dortmund. He also writes for YellowWallPod.com. You can follow him on Twitter.