The case involves a legal dispute between professional football player Bratislav Ristic and FK Olimpic Sarajevo over the termination of his employment contract and unpaid salary. The conflict stemmed from a fixed-term contract signed in August 2012, which included provisions for a monthly salary, bonuses, and a €20,000 signing fee payable in two instalments. The club failed to pay the second €10,000 instalment due by 30 August 2012 and later fined Ristic BAM 30,000 for alleged misconduct without providing details. Ristic sought termination of the contract and payment of unpaid amounts through the Player’s Status Committee of the Football Federation of Sarajevo Canton, which partially upheld his claims but denied the €10,000 payment, citing his early termination. Ristic appealed to the Football Federation of Bosnia and Herzegovina (FFBH), which upheld the decision. FIFA declined jurisdiction, prompting Ristic to file an appeal with the Court of Arbitration for Sport (CAS). The CAS Sole Arbitrator, Stuart McInnes, was tasked with determining whether the club’s non-payment justified unilateral termination under the principle of "just cause" and whether Ristic was entitled to the unpaid amounts. The Respondent argued the appeal was improperly filed and contested the financial claim, citing Ristic’s brief tenure. The Arbitrator ruled the appeal admissible, as it was filed within the required timeframe, and applied Swiss law due to the contract’s lack of a governing law clause. The Arbitrator found the club’s failure to pay the €10,000 instalment constituted a breach of contract, justifying termination. Interpreting the contract under the principle of in dubio contra stipulatorem, the Arbitrator determined the €20,000 was an unconditional signing fee, not tied to the contract’s duration. The CAS ruled in Ristic’s favor, ordering the club to pay the outstanding €10,000 with 5% interest from the due date and cover legal costs. The decision underscores the enforceability of contractual obligations and the consequences of non-compliance in professional sports contracts. The case highlights the importance of clarity in contractual terms and the legal recourse available to players when clubs fail to meet their financial commitments.