Greasy Griezz looking to upset Barcelona’s apple cart.

Atletico Madrid’s Antoine Griezmann goes up against Barcelona tomorrow, looking to derail the title charge of a club he may yet join in the summer.

Barca were forced last month to deny claims they had agreed to a deal to sign the French international, whose relentless run of form since the turn of the year is the principal threat to them toasting a 25th LaLiga triumph.

In January, Barca and Atletico were separated by 11 points but win tomorrow’s top-of-the-table clash and Diego Simeone’s side will cut that gap to two.

Barca’s 1-1 draw at Las Palmas on Thursday, a day after Atletico claimed a 4-0 win over Leganes, means the balance has tipped back towards the capital.

But, just as Griezmann has been the factor behind their resurgence, with 12 goals in nine games, he will be key again if Atletico are to inflict Barca’s first league loss this season.

The forward has never scored at the Nou Camp, a drought that extends to nine outings, but back-to-back hat-tricks – the second a quadruple – against Sevilla and Leganes will certainly have captured the Catalans’ attention.

It is no coincidence his surge has quickened since the arrival of Diego Costa, whose willingness to engage defenders in the grittier side of the game has allowed his partner the freedom to flourish.

“Griezmann has been at this level in previous seasons and now the whole team is helping him perform as he is now,” said Simeone.

“Now we have to prepare in the best way possible to face Barcelona, who have won everything and still haven’t lost a game.”

While Costa appears the perfect foil, Griezmann, 26, might glance across at his opponents and wonder where and how he would fit in.

The 30-year-old Lionel Messi and the 31-year-old Luis Suarez have 59 goals between them this campaign. Neither look ready to make way for a younger model.

Meanwhile, the club-record €160 million (S$260 million) signing Philippe Coutinho, who is wearing the No. 14 jersey because Barcelona are reportedly saving the No. 7 shirt for Griezmann, scored his first league goal against Girona last weekend.

Even Ousmane Dembele is showing signs he is beginning to settle.

“The match against Atletico comes fast and will be important for both teams,” said Valverde, whose team will be facing an Atletico team gunning for their ninth straight win.

“But we are the leaders and we are looking forward to continuing being first.”

Elsewhere, the Video Assistant Referee system will be officially implemented in LaLiga from next season, the league has confirmed.