I was in trouble," Stuart Broad says as he looks out at a sun-splashed Trent Bridge on a hushed morning in Nottingham. His recent affliction, the strange and unsettling condition known as "a lacerated fat pad" in his right heel, casts a shadow across his boyish face as he remembers his intense concern in New Zealand earlier this year.

"During the first weeks of that tour," Broad says, "I was really struggling to walk after bowling. I couldn't figure a way through it because no one had seen this type of injury before. I'd slit right the way through my fat pad and they were calling specialists from all around the world because you can't operate on it. You also can't inject cortisone into it because the fat pad will dissolve it. We were at a loss."

Three months later, and just days before a momentous summer of cricket begins with the first Test of a short return series against New Zealand, starting at Lord's on Thursday, Broad's strutting significance to England is apparent again. He is cheerful and open, restored by his return to form and health, yet also aware that last year he lost his place in England's seam attack. Any temptation to look beyond New Zealand towards next month's ICC Champions Trophy, and successive Ashes series, is curbed by Broad's lingering memories of his curious injury.

"It happened in Navi Mumbai," he says of the sundering of his heel at the outset of England's tour of India last November. "We played a warm-up game and I landed in a bad foothold and split the heel open. I walked back to my mark thinking: 'Woah, that's tender.' I tried to bowl six more balls but could barely walk. The scan missed [the lacerated foot pad] and we just treated it as a bruised heel. That was the biggest regret. I tried to hobble my way through the tour."

After a dispiriting performance during England's victory in Mumbai, to level the series, he was dropped for the third Test in Kolkata. David Saker, England's bowling coach, conceded that Broad's form was "an issue" . It's a justified comment that, even now, makes Broad wince.

"Sakes felt he was stuffed by the media. I had a long chat with him about it because, obviously, it was quite an unsupportive route for him to go down. But his quotes weren't particularly how they were portrayed. Anyway, I knew my form wasn't very good. We'd had a fantastic win in Mumbai but I'd been horrifically ill with an infected intestine. I got it the second night of the Test so couldn't do anything. I was lucky it had begun to turn square so I only had to bowl 10 overs. But I knew I was likely to miss out in Kolkata. Then, in the nets in Nagpur, it just went [Broad makes the sound of a small explosion]. That was it. Go home. The management of the heel in those first six weeks wasn't very good."

On the lonely flight home he felt "very low". His future seemed shrouded in uncertainty – which makes his subsequent resurgence all the more notable. "It feels so long ago now – even if we've only played three Tests since. I'm in much better shape and my game has come on a lot."

It's still intriguing to consider his relationship with Saker – a direct and hard-working former bowler from Australia who likes his pacemen to match intelligence with toughness. Saker is more a strategist than a tweaker of technique and differs from his predecessor Ottis Gibson, to whom Broad is especially close. "Sakes is very tactical," Broad agrees. "He wouldn't particularly get involved in your action. He'll focus more on saying we've got to bounce this guy, or drag him wide and bring three slips in. I was lucky with Gibbo. We played together at Leicester and he was the senior bowler. He helped me groove my action when I was 17. So we've always had a very strong relationship and I still chat to Gibbo now, even though he's West Indies coach. He picks up on things in my action that help me. But they've both been fantastic and since Sakes has come in, as a bowling group we've gone through the roof. Jimmy Anderson's record under him is brilliant."

Steve Finn appeared to have overtaken Broad as Anderson's strike partner as the first Test of the New Zealand tour approached. Broad was more concerned about his heel. "After the warm-up for the Twenty20s I gave myself a 10% chance of playing in the Tests. But the physio worked hard on the heel. He rubbed through the area to break down the tissue over 10 days. I owe him a lot because he grabbed me at every opportunity and said: 'C'mon, we're getting this heel right.' I was also fortunate that I'd been to Germany to get these softer boots made. They helped my heel get used to the impact."

Broad had failed to take a wicket in his two Tests in India. When he arrived in Dunedin, six-and-a-half months had passed since his previous Test wicket, against South Africa at Lord's last August. But he picked up three in that first Test in New Zealand and by the end of the series, in which England escaped with a 0-0 draw, he had emerged as his team's most successful bowler on frustratingly slow wickets. He took six in Wellington and two in Auckland – where he set an unusual Test batting record, in contrast to the 169 he scored as a No9 against Pakistan at Lord's in 2010.

Alongside Matt Prior on the final afternoon in Auckland he took 103 minutes, and 62 balls, to get off the mark. No one else in Test cricket had taken so long to score a first run. "I get stick for it," he says wryly. "I'm known as a striker of the ball. Swanny [Graeme Swann] and me got the second-fastest Test century partnership ever [against Australia in 2009]. So to think I'd ever have that 103-minute record is crazy. But when we got the 50 partnership I was still on 0. The New Zealanders were hanging round the bat, making sarcastic comments, but my discipline pleased me. I had six slips and there were gaps everywhere. I was thinking: 'Wow, easy runs here.' But it was all about having no backlift and being as dogged as we could."

Prior remained unbeaten on 110 but Broad was out with only 22 balls left. He had scored six runs in 137 minutes. "Getting out was horrendous. You get back to the changing room and turn into a mess. Cookie [Alastair Cook] was in the corner, head down. Jimmy, out after two balls, went straight to the toilet and locked the door. But I watched Matty and Monty [Panesar] save us. There's no doubt we underperformed but we showed the character you need. To get out of Dunedin with a draw, after batting 170 overs, and to survive 143 overs in Auckland, was impressive. But we need to show lots more ability and skill this summer."

Broad's fitness and form will be central to England's hopes against New Zealand and Australia – as well as in the Champions Trophy. England have never won a major 50-over tournament but Broad is bullish. "It's a fantastic opportunity for us because I can't remember the last time we lost a one-day series in England. Just like India were favourites for the last World Cup in their conditions, we stand a good chance of winning it."

The Ashes, however, loom over this cricketing year. "You walk into a coffee shop and it's the first thing someone says to you. And if we get weather like this [Broad gestures at a stunning day], it'll be fantastic. There are little things the team mentions – like the fact England haven't won four back-to-back Ashes in 120 years. There's a big chance for us to make a huge amount of history."

As a boy Broad played mini-Ashes Tests in the garden. "Weirdly, I always picked Australian players to impersonate. I'd be Hayden or McGrath or Warne. When you're young you're influenced by the best teams. So a lot of my favourite cricketers were Australian."

Broad has shared the Nottinghamshire dressing room over the past month with Ed Cowan – who opens the batting for Australia. "I met Ed for the first time at training. I sort of wanted to hate him but he's a top guy. It's strange that, in a couple of months, there'll be a big fight between us."

Has he bowled to Cowan in the nets? "Yeah – a few times. There was all that palaver about the ECB banning us from doing that but we just went ahead. He's good. A lot of ex-cricketers are saying we should knock Australia over but it's hard to argue that Michael Clarke is not the best batsman in the world. They also have a battery of fast bowlers. All the ex-players saying England should wipe the floor with Australia have forgotten what it's like to play the Aussies. They're fighters so it will be very close."

Broad can be prickly when criticised, especially by former players. He smiles cryptically: "Newcastle [football club] banned some journalists for writing bad articles. It's an interesting way to go about it."

Would the angelic-looking Broad prefer draconian censorship in English cricket? "No," he says quickly. "It would cause too much negativity. We tour with the cricket media so we know them. In India my performances were rubbish – so if someone wrote the same then fair play. But if someone takes you down and it's unfounded then I have no difficulty going up to them and saying: 'What's the problem here?' My 95-year-old grandad loves cricket. He'll say to me: 'Oooo, that Bob Willis …' or 'The Telegraph had you again.' I'm like: 'Thanks, Grandad.'"

Grandad Ken was at Lord's last May when Broad took 11 wickets against the West Indies. "I came off with the ball and saw him clapping away – proud as punch. Thinking of him getting the 6am train to Lord's made it very special. Later, I looked at the honours boards. I'm there for my century and then they have the three-fer, five-fer and 10-fer boards. The last one said: "Ian Botham 1978 … SCJ Broad 2012." Wooahh! I was minus eight when Botham's name went up. Those achievements mean so much."

On the brink of a potentially unforgettable summer, Broad stretches out his long legs and lifts his damaged heel. "I've bowled in three innings for Notts so far and got four wickets each time. So confidence is high and the heel's as good as gold. I only feel it if I walk barefooted across a hard surface."

Broad gazes down at Trent Bridge – where the first Ashes Test will be held. His lacerated fat pad, some creeping doubts and the sniping critics have, for now, been banished to the shadows. "I woke up this morning and it was such a beautiful day. I thought: 'I'm going out there to throw a ball around for a few hours. What could be better?' I felt very lucky again."

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