FC Barcelona confirmed on Thursday that Netherlands midfielder Frenkie de Jong will be sidelined for up to six weeks with a hamstring injury.

In a brief statement on their official website, Barcelona revealed that De Jong suffered a “right hamstring injury during training this morning and will be out for five to six weeks.”

The 28-year-old’s absence is a significant blow at a crucial stage of the season. He is set to miss the upcoming UEFA Champions League last-16 tie against either Paris Saint-Germain or Newcastle United, as well as key La Liga fixtures against Villarreal CF, Athletic Bilbao, Sevilla FC and Rayo Vallecano.

De Jong will also be unavailable for next Tuesday’s Copa del Rey semi-final second leg, where Barcelona are attempting to overturn a 4-0 first-leg deficit against Atletico Madrid.

The injury comes at a delicate moment in the domestic title race, with Barça sitting just one point clear of Real Madrid at the top of La Liga ahead of Saturday’s clash with Villarreal.

De Jong is also expected to miss the March international window, ruling him out of the Netherlands’ upcoming pre-World Cup friendlies against Norway and Ecuador.