Wales must find a way to combat the "genius" of Luka Modric if they are to beat Croatia and breathe new life into their World Cup qualifying campaign, according to manager Chris Coleman.
Friday's 2-1 win over Scotland at Hampden moved Wales up to third in Group A, but they still trail pacesetters Croatia and Belgium by seven points. Victory over Igor Stimac's side would reignite Welsh hopes of securing a play-off spot, but to do so they need to prevent Modric stealing the show as he did when the teams met in October.
Modric guided Croatia to a 2-0 victory that night, and Coleman knows Wales cannot afford a repeat. He said: "He was outstanding. It didn't matter what we did with him. The surface of the pitch was awful and he was still picking the ball up in his own half, creating, switching the play. He was phenomenal, it was a great performance from a quality player."
Coleman added: "On his day he is unstoppable, just like our boy Gareth Bale. The warning signs were there, he is a terrific player. He can play deep, take the ball off his back four, he can play the last pass into the striker, he can effect the game in all areas of the pitch. It is genius to be fair."
Coleman is also aware a loss in Swansea would be a mortal blow to Wales' hopes of making up the gap to the group frontrunners.
"Every game is a must-win," he said. "I said before we started we needed six points if we were going to do anything going upwards, which is a tall order when you consider we had Scotland away and Croatia at home.
"But we got the three points on Friday and if we can get the win we have Macedonia twice and Serbia at home still to come. We would still have loads to do, but it would certainly put a bit of pressure on them."
And Coleman expects an intriguing clash between the two star men on show, with Gareth Bale hoping to deprive Modric of the limelight.
"Sometimes when great players are on that form it is very difficult to stop them," he said. "If they have the capacity to do what a Bale or Modric can do it is very difficult when they are in the mood.
"I think Ronaldo and Messi are at the top and then you have a bunch of players behind them - Modric and Bale are two of them. They are in good company. It will be interesting to see what happens, especially if they are both playing centrally."