Thomas Tuchel should resign if England suffer World Cup heartbreak this weekend.That’s the view of talkSPORT’s Gabby Agbonlahor who believes the Three Lions boss should walk if England fail to get past Mexico.It wasn’t easy but England found a way bast a resolute Congo side to set up a last-16 tie with co-hosts MexicoGettyTuchel’s side face a buoyant Mexico side at the iconic Azteca Stadium in the early hours on Monday morning – live on talkSPORT – hoping to keep their World Cup dreams alive.Much has been made of the last-16 clash with Mexico boasting home advantage and being well acclimatised to the high altitude in Mexico City.Following an impressive start to their World Cup campaign with a 4-2 win over Croatia, England have looked flat in their subsequent games and had to leave it late to edge past DR Congo in midweek.With the knockout rounds now in full swing and no second chances for Tuchel to deliver on football’s grandest stage, a last-16 exit is unthinkable to the world’s fourth-best ranked nation.For former Aston Villa striker Agbonlahor, defeat at the Azteca doesn’t bear thinking about.Pack your bagsAgbonlahor recently argued that The FA should sack Tuchel and replace him with Eddie Howe if the German fails to reach the World Cup final. Tuchel initially signed a short-term deal to manage the Three Lions until the end of the World Cup, but this was extended before the tournament began.Now, going one step further, Agbonlahor believes Tuchel should start drafting his resignation letter if England lose to Mexico in the last-16.Asked if Tuchel would have already been sacked by the time he comes on air for the Sports Breakfast show on Monday, in the event of a defeat, Agbonlahor said: “No, I think the following day.”Agbonlahor was then asked if he thinks Tuchel would resign to which he replied: “I hope so.”The superb Azteca Stadium awaits Tuchel’s menGettyAgbonlahor believes Tuchel’s job should be on the line on Sunday nightTalkSportHe continued: “If we lose to Mexico… listen, the altitude, they’re playing at home, the record. I get it.“But still, we need to beat Mexico.“He has been brought in and is being paid millions of pounds to win the World Cup or the Euros.“If he doesn’t do that, bye bye. Who do we go to next?”Tuchel was a surprise choice as England head coach to succeed Gareth Southgate.The German quickly won over doubters by leading the Three Lions to a perfect qualification campaign with eight wins from eight games and no goals conceded.Tuchel has shown he can make key changes at key moments to turn the tide in England’s favourGettyIt has largely been plain sailing for Tuchel so far, however, his biggest obstacles appear to be coming at the World Cup with England having shown their true level in just one half of football so far.Asked what the best thing Tuchel had done for England since his tenure began, Agbonlahor said: “Croatia, second half. The way he used the attacking subs, the way he changed it.“I like his passion and I like him.“I think everyone will agree, if we go out in the last 16 after some of the abuse Gareth Southgate got – we got to finals and semi-finals and he got slaughtered for not getting over the line.“How can we say, unlucky, altitude, no problem. Lets try and win the Euros.“No, we go and get someone else who can do it.“How many generations are waiting? We’re a laughing stock.”