All Chelsea fans knew what was coming around the hour mark throughout the 2018/19 season when the fourth official went to hold up his board.
Whether Maurizio Sarri started with Mateo Kovacic or Ross Barkley on the left of a midfield three, one would eventually make way for the other for the closing stages of the game.
It didn't just happen a few times here and there between August and May, the change took place on 22 occasions across all competitions.
Signed on a season-long loan deal from Real Madrid at the start of the season, Kovacic just couldn't hit top form in the capital and many fans didn't want the club to sign him on a permanent basis.
However, with the Blues hit with a transfer ban and unable to add to their squad for two windows, the move was finalised in July because of a loophole in their transfer suspension.
In and out of the team under Sarri 12 months ago, the Croat is now one of the first names on the teamsheet for Frank Lampard after finally proving why he was brought to the club in the first place.
Kovacic has now added goals to his game, although this is an area that still needs to be worked on, and he's also a leading contender to scoop the club's Player of the Year award at the end of the campaign.
While some Chelsea fans couldn't have predicted his dramatic turnaround in west London, Lampard spoke highly of the player in pre-season and claimed that there was "more to come" from the talented midfielder.
Speaking to football.london following his performance in Chelsea's 2-1 win over Barcelona in Japan, he said: "I thought he was outstanding in the first half. I really liked Kovacic last year and I watched him a lot.
"When you say he had a difficult season I kind of get that, but at the same time I saw lots of things in his game that I really like.
"What I found here on the tour from the first day he turned up is a hungry attitude, desire to work and incredible talent on the ball.
"I want to work with him and I want to help him to improve and improve. There's so much talent there,
"I really like him. He was outstanding today and I'm really pleased.
"We know we've got numbers in midfield area and I can't help but be excited by some of the elements today and I think there's more to come."
Lampard has been proved right with his comments from back in July as Kovacic has taken his game to another level at Stamford Bridge.
He's looked a totally different player under the club legend and he's now having much more of an impact for the team going forward, as can be seen by the fact he finally opened his Blues account back in November with a goal at Valencia.
Gone are the days when he and Barkley would be swapping places week in, week out as well, with Kovacic starting in 29 of his 37 appearances for the Blues this term.
Certainly underappreciated by many in the capital 12 months ago as he struggled under Sarri, the 25-year-old has more than proved his worth and showed that he can be a huge part of Lampard's Chelsea team over the coming years.
