So it seems you are either with me or firmly against me: there doesn’t appear to be a middle ground after my comments about Tim Krul. It is a week since I criticised Newcastle United’s goalkeeper for appearing to congratulate Jermain Defoe at half-time during the Wear-Tyne derby after the Sunderland striker beat him with a brilliant volley. I’m still struggling to work out why Krul did what he did. I have nothing against Krul, personally or professionally. He’s been one of the few players who have performed consistently for Newcastle in recent seasons, which led to him being part of Holland’s World Cup squad last summer. Newcastle keeper Tim Krul  congratulated Sunderland striker Jermain Defoe on his goal at half-time . Krul smiles at Defoe shortly after the striker's goal gave the Black Cats the lead in the Wear-Tyne derby . Sportsmail's Jamie Carragher criticised Krul for his half-time actions while speaking on Sky Sports . But coming together with an opponent and smiling after he’s scored against you in a match of such importance? No, I’m sorry. I can’t understand why any player would feel the need to do that. At the end of the game? That’s not an issue — there is no more appropriate place for sportsmanship. Think about the iconic image of Pele and Bobby Moore swapping shirts after Brazil had beaten England 1-0 at the 1970 World Cup or how two boxers will embrace after they have gone the distance — that is fantastic to see. When Liverpool beat Chelsea in the 2005 Champions League semi-final at Anfield, the first thing I did at the final whistle was go over to see John Terry to offer my respects for how well he’d played over the two legs. Would I have told him that at half-time with the game in the balance? No chance! We were talking about this subject at Sky on Monday morning. I bumped into former England rugby centre Will Greenwood and he told me a story about the end of the Rugby World Cup final in 2003, when Australia’s Elton Flatley scored a penalty with the last kick to take the game into extra-time. Pele (left) and Bobby Moore hug and swap shirts after the 1970 World Cup match between Brazil and England . Elton Flatley (left) levels the 2003 Rugby World Cup final with the last kick of normal time . Luis Garcia celebrates his winner for Liverpool against Chelsea in the 2005 Champions League semi-finals . Will said he went up to Flatley after that successful conversion and said to him: ‘Well done — you’ve got balls as big as houses for that.’ That is great sportsmanship but I’m not sure I could have done the same if I’d seen the World Cup ripped out of my hands. Andrew Flintoff, who famously went to console Brett Lee at the end of an Ashes Test in 2005, joined in the debate on Twitter. He clearly felt I had been harsh on Krul and he told me cricketers applaud the opposition batsman when he passes 50 or 100, quite often with a handshake. That’s all well and good. But will a batsman walk up to a bowler and pat him on the back after having his stumps uprooted? We have never seen that happen nor are we likely to. You don’t congratulate the opposition at a time when your team have been put on the back foot. I carried that approach during my career. There were more talented players than me but I had desire, focus and would never lose my intensity. I never, for instance, ever considered shaking hands or hugging an opponent in the tunnel before a match. The attitude stemmed from my childhood. Growing up as an Evertonian, I would work myself into a frenzy in the week before a derby match. I despised Liverpool then and I wanted the players who I supported to feel exactly the same way. Andrew Flintoff (right) consoles Brett Lee after England beat Australia in the second Ashes Test in 2005 . Defoe (centre) shoots and scores the opening goal on Sunday at the Stadium of Light . Defoe celebrates his strike which helped the Black Cats to victory in the Wear-Tyne derby . If, then, I’d seen Neville Southall put an arm around Ian Rush’s shoulder after he’d scored a goal, I’d have been devastated. I took that approach when I ended up playing against Everton. Put it this way — I couldn’t have shared a joke with Tim Cahill if he’d scored 30 seconds before half-time like Defoe. I appreciate some people reading this will feel it was extreme but that’s how I operated. Gary Neville has told me regularly that if I ever want to go into coaching or management, I will have to lower my tolerance levels since modern players are different and it isn’t worth falling out with them over certain things. I’m not saying my way is right or wrong but to be at my best I needed to be tense and wound up. If I thought to myself I needed to say ‘Well done’ to someone I was in direct competition with, I wouldn’t have been thinking about winning the game in which I was involved. That wasn’t me. Gerard Houllier was a manager who held similar views. He once saw one of our foreign players hugging an opponent in the tunnel before a game at Anfield and went berserk afterwards. ‘I never want to see that again from any of you — you are going to war with them,’ he said. ‘Save the hugging for in the bar afterwards.’ Carragher (left) argues with Gary Neville during a 2010 league match between Liverpool and United . Liverpool manager Gerard Houllier holds the FA Cup aloft after winning the trophy in Cardiff in 2001 . Houllier even told us before the FA Cup final in 2001 that he didn’t want us looking into the stand to see our families; given that I grew up watching players make the long walk at Wembley while waving to the crowd, that was quite a statement. But do you know something? I loved that. There is a time and a place for showing mutual respect and it is after the final whistle has gone and you are in the bar afterwards. Before that, you have business to take care of and that should be the priority — that’s why I felt so strongly about Krul. Others, of course, will take a different view and say I have been too harsh. I respect that. It doesn’t mean to say, though, that I can understand it. Underdogs City need show of strength . It is almost four years to the day since Manchester City struck a huge psychological blow in the battle to be top dogs in town. On April 16, 2011, Yaya Toure’s goal knocked Manchester United out of the FA Cup and set his club on a path of sustained success. It says everything for what was achieved back then at Wembley that City won six of the eight derbies that followed. Even when United won the title in 2013, there was a feeling that it was down to unrest behind the scenes with Roberto Mancini rather than the brilliance of Sir Alex Ferguson’s squad. Player for player, City’s quality was superior to their old rivals. Manchester City's Yaya Toure celebrates after scoring against United in the 2011 FA Cup semi-finals . Vincent Kompany (centre) lifts the trophy after Manchester City won the Premier League in 2012 . There is a similar feel about Sunday’s meeting at Old Trafford but this time City are vulnerable. United, having won their last five Barclays Premier League fixtures, are firm favourites and will feel confident of finally ending their neighbours’ title aspirations. If Louis van Gaal’s side win, the ramifications for City could be serious. There is no doubt United will spend big again in the summer and, with the full implications of Financial Fair Play kicking in, they might be able to recruit the players that City need. United will certainly fancy their chances but they should not take anything for granted. When the teams come out, City will still have the best striker on show in Sergio Aguero, the best midfielder in Toure, the most creative talent in David Silva and the finest defender in Vincent Kompany. Sergio Aguero (centre) in action for Manchester City against Crystal Palace on Monday night . Wayne Rooney (right) on the ball as Manchester United manager Louis van Gaal takes training on Friday . That quartet have not been at their best this season but, during the last four years, they have provided the best spine in the Premier League. They aren’t the problem at City — it’s the players around them who need to be improved. If City want to send a message to United — and for next season — Aguero, Silva, Kompany and Toure will have to show what we know they are capable of. Van Gaal is starting to put his stamp on United — they have improved since the switch to 4-3-3 — and has big ambitions. City have relished having United in their shade. To keep them there, they need a show of strength.
JAMIE CARRAGHER: Tim Krul was wrong to congratulate Jermain Defoe . That argument from Sportsmail's columnist has divided opinion this week . Carragher still cannot work out why the Newcastle keeper did what he did .