Mike Brown is a man on a mission after accepting he needed to restore his reputation, both on and off the pitch.

Everything went wrong following what should have been a momentous appearance at full-back in the England's First Test defeat by New Zealand in June.

A late night out after the match led to four players, Brown among them, facing a serious sexual allegation, albeit one that was subsequently dismissed by a Rugby Football Union investigation.

However, the 23-year-old Harlequins player was fined £1,000 for "staying out all night during an England rugby tour" and missing a physio appointment.

Then, as he came to terms with that serious error of judgement, Brown found himself omitted from the 32-strong elite senior squad and relegated to the Saxons, England's second team.

It appeared the man who was supposed to be the answer to England's full-back problems was paying an even heavier price for his mistake, but a telephone call from new national team manager Martin Johnson, proved highly significant.

"Johnno rang me before the squad was announced and said he had picked Mathew Tait as full-back and Josh Lewsey as a full-back/wing because they had a yard of pace on me," said Brown, who faces Ulster in the Heineken Cup at the Twickenham Stoop tomorrow.

"I was thankful he took the effort to ring me, that hadn't happened before with England, but I was still desperately disappointed to miss out.

"Johnno helped a lot because he said it was nothing to do with the New Zealand tour and that he wanted me to work at my game.

"I knew that after what Johnno had said, I had to go away and look at my angles of running at full-back and work on my pace and that is why I started working with sprint coach Tony Lester."

Lester is the UK Athletics coach for West London and has worked with international sprinters Marlon Devonish and Mark Lewis-Francis, along with Quins wing Ugo Monye, one of the fastest players in the game.

Monye is a close friend of Brown and together they took to the track last night to put in the extra work that both hope will impress Johnson.

"Tony has worked at Quins and helped Ugo a lot," said Brown. "The work I have already done with the Quins coaching staff has improved my pace this season and I think that was confirmed in our win over Scarlets last Saturday in the Heineken Cup. I think that I proved a few people wrong and now I want to work even harder."

Inevitably, the ramifications of that June night in Auckland remain a factor in Brown's life and considerable soul searching and lengthy discussions with the people he trusts have helped the young full-back make an impressive start to the season.

Brown admitted: "What happened in New Zealand was unfortunate and I will learn from my mistakes.

"I put myself in that situation and I believe that with the support of my family, friends and Dean Richards and Mark Evans [chief executive] at Quins I have improved my character. I am not so naive and have a better understanding of life in general. If you let those things linger then you can suffer even more and I have learnt a lot.

"As horrible as it was, it was good to come back to the club and be with my team-mates. Of course there was a bit of stick but they understood my side of the story. Now, it's up to me to show people they are wrong."

Richards, the Quins director of rugby, has nothing but praise for the way Brown has responded.

He said: "I don't know many players who are more professional than Mike Brown or more committed to being an international player. He will constantly stay on after training and do all the little extras that are necessary.

"I know there is some criticism about his speed, but for him to chase down Scarlets wing Darren Daniel was very impressive and while he may have a relatively awkward running style, he is much quicker than people give him credit for. Ugo Monye is exceptionally quick and while Mike is not that fast, he is a quick back who will never let anyone down."

Brown now faces an Ulster team that suffered a home defeat by Stade Francais last weekend and Quins should have too much firepower for the Irish side. However, they do possess clever backs in Paddy Wallace and the under-performing Andrew Trimble.

London Irish continue their European Challenge Cup campaign in Connacht tonight showing one change with James Buckland taking over from Danie Coetzee at hooker while Saracens travel to Viadana looking for another emphatic win with Andy Farrell back at centre.