Returning Chelsea striker Diego Costa did not just let his predatory right foot do his talking for him on Sunday. A pair of gesturing hands were just as eloquent as he appeared to be making a point to his critics.

The striker who is never far away from controversy shot the Premier League leaders towards a 2-0 win over Hull City on his return to the first team and celebrated his first-half goal with gestures that mimicked gossiping mouths.

At least, that seemed to be his considered response to a wave of reports that he had been involved in a row with Chelsea fitness staff and that his head had been turned by a potential big-money move to China.

Costa missed last weekend's win at Leicester City with what club officials said was a back strain yet his absence was widely interpreted as the latest strain in the often tense relationship between the striker and the club.

Costa's goal -- on his 100th appearance for Chelsea since joining from Atletico Madrid -- was his 15th in the league so far this season, leaving him joint top scorer along with Arsenal's Alexis Sanchez.

The strike also underscored the vital role Costa has played in Chelsea's dramatic turnaround from last season's woeful performances.

Then, the Brazilian-born striker hit the headlines for throwing a bib towards former manager Jose Mourinho after he was left on the substitutes bench for a game.

Chelsea fans showed they bore no grudge against Costa over his latest absence, chanting his name before kick-off on Sunday.

The striker proved central to Chelsea's attacking moves throughout the game, latching on to a Victor Moses cross with a sharp finish just before halftime to give the leaders their crucial breakthrough.

Chelsea captain Gary Cahill, who wrapped up the win with a late goal, said it was clear that Costa was delighted to be back in the team.

"There was a lot of talk when something happens or he misses one game, and all of a sudden you're hearing about all these different stories," Cahill told Sky Sports.

"I suppose it gets a bit tiring after a bit and the best way to respond is to produce a goal like that. We are delighted to have him back in the team and we're delighted to have him scoring again which he's been doing all season."

Manager Antonio Conte said he hoped Costa's performance would finish the speculation about the striker, who has two years left on his contract with Chelsea.

"I repeat, he is very happy to stay with us and he is very happy to play with Chelsea. Now it is very important to be concentrated on the present," Conte said. "The present is more important than the future."