With the deadline looming, Chelsea goalkeeper Courtois – who has been heavily linked with a switch to Real Madrid – failed to report for training as doubts over his future at Stamford Bridge intensified.
While Kovacic could be coming in the other direction after refusing to train until he got a move to Stamford Bridge.
But the pair are far from the first and they won’t be the last to take drastic action in a bid to move away.
We take you through some of the others who have forced their way out.
FIVE PLAYERS WHO FORCED THROUGH TRANSFER MOVES
Pierre van Hooijdonk
Striker Van Hooijdonk returned to Nottingham Forest after the 1998 World Cup and was left less than impressed by an apparent lack of investment in the squad, so asked for a transfer, having seen the club turn down an approach from PSV Eindhoven during the previous promotion campaign.
When his request was rejected, the Dutch forward did not take it well and headed back to Holland to train instead at his former club NAC Breda. After three months, he eventually returned to Forest, who refused to listen to offers. Manager Dave Bassett said at the time: “If he thinks we are going to offer him an olive branch, he knows where he can stick it.”
When he got back in the side, Van Hooijdonk scored against rivals Derby – but none of his team-mates celebrated with him. Forest were relegated at the end of the season, finishing bottom, and Van Hooijdonk eventually left for Vitesse Arnhem.
France defender Gallas endured an acrimonious departure from Chelsea on deadline day 2006 after rejecting a new contract. Eventually a deal was brokered which saw Gallas head to Arsenal – a team he would later captain – as part of the deal which took full-back Ashley Cole to Stamford Bridge in a last-ditch deal.
Following the conclusion of the saga, Chelsea issued a strongly-worded statement claiming Gallas showed a “lack of respect” by refusing to play in the 2006 FA Cup semi-final against Liverpool, then did not join up for pre-season in Los Angeles as agreed.
He also threatened to score own goals, “get himself sent off, or make deliberate mistakes” if he remained there into the new campaign. Gallas rejected the claims, saying Chelsea were “hiding behind false accusations.”
In a more recent drawn-out saga, French playmaker Payet took drastic measures after West Ham refused to sanction a switch back to his former club Marseille.
Claiming a back problem in the wake of a 5-0 loss to Manchester City in the FA Cup on January 6 2017, Payet never featured for the Irons again as his dispute with the club rumbled on.
Eventually, West Ham agreed to the £25million transfer later in the January window, as the player left less than a year after signing a new long-term deal.
Algeria winger Mahrez was all smiles as he finally saw his protracted move to Manchester City come off in July 2018 in a reported £60million transfer.
However, Mahrez had been left less than impressed by previous deals to City having failed to materialise during earlier windows.
He spent time away from the club, missing Premier League games in the process, reportedly claiming promises made allowing him to leave had been broken.
At the start of the 2007/08 campaign, Tottenham frontman Berbatov was involved in a transfer row as Manchester United looked to take the Bulgarian to Old Trafford.
Spurs claimed then United boss Sir Alex Ferguson had broken Premier League rules by reportedly talking up the move, which the Scot denied. Berbatov, though, insisted he was not in the right frame of mind to focus on playing, so, after being on the bench at Middlesbrough, he sat out early-season matches against Sunderland and Chelsea.
With the forward appearing determined not to play for Spurs again, a deal of around £30million was completed just ahead of the transfer deadline.