US Open 2014: Heather Watson and the Argentine influence

Argentine coach Veronelli believes Watson is capable of far more than she has shown so far

Heather Watson returns to the US Open brimming with confidence, thanks in large part to the influence of little-known Argentine coach Diego Veronelli.

The British number one will begin her campaign against Romania's Sorana Cirstea in Tuesday's first match on Court 13 at 16:00 BST.

And a year on from her tearful departure following a first-round defeat by Simona Halep, Watson is back in the top 50 and talking about reaching the second week of a Grand Slam.

"It's so much of a target," said Watson. "It was my goal this year and I haven't accomplished that yet, but I still have one more opportunity."

Watson defeated Australian Open finalist Dominika Cibulkova in Montreal this month

Helping her is Veronelli, the 34-year-old son of a sports-mad judo expert from Buenos Aires, a passionate fan of Copa Libertadores winners San Lorenzo and, like most of his compatriots, bruised by Fifa World Cup final defeat this summer: "I'm still trying to get over it but I'm proud of my boys."

He also believes Watson is capable of far more than we have seen so far, even daring to mention the number one ranking, adding: "Why not?"

The pair's relationship arose from a desperate 2013 for the Briton that saw a bout of glandular fever curtail her rise to a career high-ranking of 39, precipitating a fall to 119 by the end of the season.

Watson split with her long-time coach Mauricio Hadad last summer and Veronelli took up the role at the end of the season, after a lunch that he admits "was not very comfortable".

"She's young, and I felt she was interviewing me," he explained. "But I felt I should be completely honest and she decided, 'let's give him a try'."

It looks to have been an inspired decision, with Watson recently breaking back into the top 50 after a summer that included her best-ever wins over Flavia Pennetta and Dominika Cibulkova.

At the heart of this change in fortunes has been the decision to play a more aggressive game.

"I didn't realise she could do that until I saw her competing," admitted Veronelli.

"I knew she was going to win a lot of matches by making a lot of balls, but I knew she wouldn't become a top player if she didn't add things to her game - I wouldn't say change.

"Can she be number one? Why not?" says Veronelli

"She will probably never be able to play the same way as Serena Williams or Maria Sharapova, but she can add some weapons or new shots to her game that will make her improve and take that next step."

A former world number 165 - with wins over Nikolay Davydenko, Fernando Verdasco and David Ferrer to his name before injuries took their toll - Veronelli had limited experience of coaching women but recognised a good opportunity with Watson.

"I knew that I could only win with Heather," he said. "She wouldn't drop from 120 or whatever the ranking was when we started because she belongs, for sure, in the top 50 at least.

"So it was a good position for me and I think it was the right timing."

Although naturally upbeat, Watson has adopted a sterner attitude towards her career in 2014

Watson described her coach as "a joker, he's really funny" away from the court, but added: "When we get to work, we're working."

The last year has seen the irrepressibly upbeat and sociable 22-year-old adopt a sterner, more business-like attitude towards a career that is always under scrutiny as one of a handful of world-class British players.

"I try to keep her away from that pressure, although we are aware that people are following her," said Veronelli.

"But we try to stay away from Twitter, although she does use Twitter and social media. Sometimes you can get comments that can hurt.

"The way I see it, there are only 44 players in the whole world that are better than her. I see a full glass.

"She only cares about the opinions of people she loves and I try to keep it that way."

Watson was a semi-finalist at Eastbourne in June

Veronelli is able to combine his own family time with training blocks in between tournaments as his wife and 17-month-old son are based in Bradenton, Florida, where Watson returns having learned her tennis at the Nick Bollettieri Academy.

For the most part, Veronelli is on the road with Watson, however, and he has been absent from just one of her 17 tournaments this year.

"I'm used to it, but now that my son is starting to speak I find it hard," he said. "But this is what I've got to do, it's my life and my job. I'm OK."

There will be more travelling following the US Open, during what is known as the 'Asian Swing' of events, but at least they offer the prospect of further progress.

Watson lost to Simona Halep in the first round of last year's US Open

Watson will have very few points to defend and there is every chance of her surpassing that best ranking of 39, but Veronelli is not about to set any limits.

"Can she be number one? Why not?" he said.

"People must think I'm crazy but if I don't believe in her then I have to say, 'OK, I think she can be 30 in the world.' And once she gets there it's like my job is done.

"No, let's go for more. Do you want to give up a lot of things; happiness, time with friends and family, whatever it takes?

"Maybe not, and you just want to have a pretty good career instead of an exceptional career. So it's up to her."