Lens president Gervais Martel insists FIFA's decision to ban Chelsea from signing new players for 18 months is fair.
The Blues were found guilty by football's governing body for inducing former Lens winger Gael Kakuta to breach his contract with the French club so he could complete a switch to Stamford Bridge.
The Frenchman was 15 when Chelsea began to take an interest in the player in 2007 and Lens immediately complained to FIFA.
Chelsea have announced that they will appeal against the ruling that currently means they will be unable to sign any new players in the next two transfer windows.
They were also ordered to pay £115,000 in compensation to Lens while Kakuta must hand his former club £680,000 with the Blues jointly liable for the payment.
"We expected this kind of decision," said Martel.
"The player was under contract with us, and they came and stole him away from us.
"Chelsea didn't follow the rules. They contacted the player when he wasn't even 16 yet, and while he had been contracted to our training group from the age of eight.
"The financial sanction isn't over the top given the nature of the infringement, but it's really quite significant when it comes to not being able to recruit players.
"It's an important message given that protecting up and coming youth players who are contracted to clubs is an issue being followed closely by (Uefa president) Michel Platini."
The Blues were astonished by the ruling, both in terms of the ban and the financial punishment, and in a brief statement said they would be launching "the strongest appeal possible".
A statement from the club read: "Chelsea will mount the strongest appeal possible following the decision of FIFA's Dispute Resolution Chamber over Gael Kakuta.
"The sanctions are without precedent to this level and totally disproportionate to the alleged offence and the financial penalty imposed.
"We cannot comment further until we receive the full written rationale for this extraordinarily arbitrary decision."
Lens had wanted compensation for Kakuta as well as calling for sanctions to be imposed on the FA Cup holders.
FIFA's DRC agreed that Chelsea had indeed been guilty of inducing the youngster to break his contract and announced their verdict in a short statement.
"The French club had lodged a claim with FIFA seeking compensation for breach of contract from the player and requesting also sporting sanctions to be imposed on the player and the English club for breach of contract and inducement to breach of contract respectively," said FIFA.
"The DRC found that the player had indeed breached a contract signed with the French club. Equally, the DRC deemed it to be established that the English club induced the player to such breach.
"As a result the player was condemned to pay compensation in the amount of EUR 780,000, for which the club, Chelsea, is jointly and severally liable, and sporting sanctions were imposed on both the player and Chelsea in accordance with art. 17 par. 3 and 4 of the Regulations on the Status and Transfer of Players.
"A restriction of four months on his eligibility to play in official matches is imposed on the player Gael Kakuta while the club Chelsea is banned from registering any new players, either nationally or internationally, for the two next entire and consecutive registration periods following the notification of the present decision.
"Furthermore, Chelsea, has to pay RC Lens training compensation in the amount of EUR 130,000."
Kakuta, a skilful left-winger, is viewed as one of Chelsea's most promising young players.
He ended his first season as top scorer in the youth side and was voted the academy's player of the year.
However, last February, his season was ended by a double fracture of his ankle.Reuse content