Chelsea's Diego Costa as he is substituted during the English Premier League match against Hull City at Stamford Bridge, UK on Jan 22, 2017. [Photo/Agencies]

Asked if Costa signing a new contract would help douse the rumors, Conte replied: "I don't know. This decision is something you have to take together with the club.

"But I repeat - he's very happy to stay with us and to play with Chelsea.

"For us, now, it's very important to concentrate on the present and don't see too far.

"If we start to see too far, we risk losing the present. The present is more important than the future."

Hull's disappointment was compounded by Mason's injury. The former Tottenham midfielder required oxygen on the pitch and was taken to hospital after a shuddering clash of heads with Chelsea's Gary Cahill.

"Ryan is in a stable condition and is expected to remain in hospital for the next few days," said a Hull statement after his surgery.

"A further update will be issued Monday."

Hull, which remains in the relegation zone, was missing Robert Snodgrass due to what coach Marco Silva said was a "small" knee injury.

The Scotland international, Hull's outstanding performer this season, has been strongly linked with a move to West Ham United.

Asked if Snodgrass would leave the club in this month's transfer window, Silva replied: "I hope not because he's a good player, an important player for us, and I don't want important players to leave."

Chelsea hosts fellow west Londoners second-tier Brentford in the FA Cup this weekend before a league doubleheader with Liverpool and Arsenal.

With Spurs, Liverpool and the two Manchester clubs all dropping points, Chelsea's grip on first place has further tightened, but Conte aired a warning.

"Me and my players, we have a good experience to understand that this league will be very tough until the end," said Conte, who saw Cahill head in Chelsea's second goal in the 81st minute.

"To win this type of game and exploit the situation that the other teams dropped points is very important.

"But this league will be very tough until the end. To stay now in that position is fantastic for us because at the start of the season, not one person thought this was possible."