This time last year there were doubts as to whether Lille would even exist as a football entity come 2019. Les Dogues were 19th in the table – a position they held until early May – and had been told by the DNCG [French football's financial watchdog] that they would be relegated regardless of their league position if they failed to address the crippling debt that had accumulated.

The enormous compensation package (a reported 16 million euros) being demanded by deposed coach Marcelo Bielsa looked like the straw which would break the camel's back.

When angry fans poured on to the pitch to remonstrate with Lille's beleaguered players at the end of a game against Montpellier on March 11, it felt like the end was nigh. Yet throughout all this, Christophe Galtier – who had been appointed coach just before Christmas – kept calm and kept on trying to instil confidence and belief in his traumatised team. In the end, Galtier's composure and Lille's slightly superior quality won the day. Back-to-back wins over Metz and Toulouse kept them up, and the rebuilding process could commence.

"We had to radically change the makeup of the dressing room," Galtier told me last week. "Fourteen players left." Selling the likes of Yves Bissouma, Ibrahim Amadou, Kévin Malcuit and Lebo Mothiba helped Lille reduce their debt. Many others left because, as Galtier explains, "the attitude wasn't right".

The biggest lesson learned from the Bielsa debacle was importance of possessing a sprinkling of experienced figures. José and Rui Fonte, Loïc Rémy and Jérémy Pied have this season provided the youngsters with the stability they so badly needed last term.

But it wasn't just a matter of finding some older players and signing them. Lille have found older players who want to lead by example. José Fonte has been exceptional on and off the pitch, but all four have contributed positively to life in the dressing room.

"I've always looked to have senior players I can lean on," Galtier says. "I give them extra responsibility. They define the rules of the group and the younger players follow them. Not everyone can play every game. But senior players, whether they are starters or not, have a very important role to play in the dressing room."

Overall Lille's summer business was exceptional. On top of the veteran signings, young tyros Jonathan Ikoné, Jonathan Bamba, Zeki Celik and Rafael Leao have all been brilliant – they are talented and hungry individuals who will surely gain value in the coming years. Virtually every recruit has come off.

Again, this is not down to luck. When I asked Galtier why he agreed to taking the Lille job despite the club's terrible predicament, he cited two reasons. The first was his personal attachment to a club he represented as a player. The second was the presence of sporting director Luis Campos. Lille's recruitment guru has performed miracles in the transfer market both with Real Madrid and Monaco in the past, and his eye for a player is now galvanising Lille.

Galtier was not ashamed to admit that he didn't personally decide which individuals should be brought in. "I was implicated in the choices in terms of the profiles," the coach points out. "But 90 percent of the players Luis proposed corresponded with the kind of player I wanted. In terms of the player's characteristics, but also in terms of the spirit… that's important for me. He has to be a teammate who puts the team first. That was something I really insisted on when talking to Luis."

Possibly the most important event last summer was a transfer that didn't happen. Borussia Dortmund and Lyon were both ready to pay 30 million euros for Nicolas Pépé, and Lille were not in a position to refuse. Pépé, however, decided he wanted to stay. The brilliant young forward sensed that something exciting was happening with Galtier. He sensed that he could enjoy the best season of his career at the Stade Pierre Mauroy. Today his goals have taken Lille to the brink of the Champions League and his price tag has more than doubled.

Should Lille beat lowly Dijon at home on Sunday afternoon, they'll stretch eight points clear of third-placed Lyon, and the pressure will be on Bruno Genesio's team. For while third position in France also offers Champions League football, there are two qualifying rounds to get through first.

At a time when PSG are so strong they are disappearing over the horizon, second place in Ligue 1 is almost worthy of a trophy in itself. And given how far Lille have come so quickly, it would not be unmerited.