Andre Villas-Boas thinks Jermain Defoe is reaping the rewards of finally being assured of a first-team place at Tottenham.
Spurs head to Manchester United on Saturday looking to upset the odds and register their third straight Premier League win.
Although Villas-Boas admits his team is not yet the finished article, Spurs have shown improvement over the last two weeks, winning three of their last four matches in all competitions.
Defoe has played a big part in Tottenham's improvement, scoring four goals in the lone striker role which many said the diminutive forward was not able to fulfil.
Harry Redknapp preferred to use Peter Crouch and then Emmanuel Adebayor in the position during his last two years at White Hart Lane, but Villas-Boas has put his faith in Defoe and he has been delighted with the 29-year-old's response.
"He has been immense for the team," Villas-Boas said.
"He's getting continuous opportunities that maybe he didn't have in the past so I think he is enjoying it a bit more. He is looking extremely happy.
"We have to be very grateful for what he has been doing for the team.
"For a striker goals are decisive and he has four in the Premier League. He's not far off being top scorer and he has been creating so much.
"I can't put anything of his in to question. He has desire, his motivation is there, and his movement is fantastic so we hope he will continue in this way."
Defoe's future at White Hart Lane was in question at the end of last season, with Redknapp sticking to his policy of playing Adebayor and chairman Daniel Levy actively looking to sign another forward.
But Villas-Boas insists he was always determined to keep hold of the former West Ham striker, who brought speculation about his future to an end by signing a new three-year contract last month.
"In the summer we really wanted him here, and that's why we spoke with the chairman and his agent about his contract renewal," the Spurs boss added.
"And I am sure that is having an impact on what he feels about himself and his team."
Despite the absence of Nemanja Vidic, who is injured, Tottenham will have to produce their best performance of the season if they are to come away with a win tonight.
The Londoners have not won at Old Trafford since December 1989 - when Gareth Bale was just five months old - but centre-back Jan Vertonghen tasted victory against the Red Devils with Ajax last term and is confident that Spurs can do the same.
"We are strong enough to beat them," Vertonghen said.
"We have a good team, we've won the last two or three games now playing good football and everyone is hopeful of getting a good result at Old Trafford.
"Teams have done well there and that gives us hope.
"When I played against them last year they beat us in the Amsterdam Arena 2-0 and I think they thought they could beat us at 60 per cent.
"It was a good game at Old Trafford. We beat them in the last minute and that showed that with good counter-attacks you can win there."