MANCHESTER CITY came from behind to beat Bournemouth 2-1 and seal an FA Cup semi-final spot.Goals from Erling Haaland and Omar Marmoush sealed another appearance at Wembley for Pep Guardiola’s men.Pep Guardiola’s tactical masterclass helped Man City beat Bournemouth 2-1Credit: GettyCity are in another FA Cup semi-final thanks to their comeback winCredit: GettyThe Man City gaffer unleashed some amazing tactical decisions that brought the best out of several stars.In the latest episode of SunSport’s Tactics Exposed, our expert DEAN SCOGGINS explains what City did to make the final four once more…LIFE O’REILLYWe shouldn’t forget Nico O’Reilly is a Number 10. So to bring him on and play him at left-back was a bold thing from Pep – but it was for a variety of reasons.One was that Abdukodir Khusanov had been booked in the first half so he was the obvious one to take off.READ MORE IN FOOTBALLThe second is it put Ruben Dias on his natural right-hand side and meant Gvardiol came in as the left centre-back.It meant Nunes on the right and O’Reilly on the left like wing-backs, with Kovacic dropping in the gap.Nico O’Reilly had a game-changing performance from the benchThen ace had the run of the left flank thanks to his clever teammatesIt took away some of O’Reilly’s defensive responsibilities and became like a 3-4-2-1. It really confused Bournemouth. He’s got a great touch and went charging up the left, with most of those touches in the attacking half.Most read in FootballBEST FREE BETS AND BETTING SIGN UP OFFERSThere’s an argument for him to play there in the league as Pep’s always used full-backs as a weapon.There’s no reason he can’t play there, he gave City more balance. He took the pressure off Nunes on the other side and they had an out-ball that went the other way.Pep Guardiola hails Man City’s ‘legendary’ players after comeback win at Bournemouth PRESSURE MAKES DIAMONDSCity created a diamond in midfield. Kovacic dropped back between the two centre-backs.You then bring two people in very narrow, which combats Bournemouth because they press you really narrow.What City did was get De Bruyne to go on Cook, who was the full-back, and bring him into the middle of the field.Gundogan does the same, bringing the midfield in, and that left O’Reilly with all that space up the left-hand side.Man City’s players formed a clever midfield diamondIt drew Bournemouth defenders into narrow positionsPep told Grealish to come inside and don’t worry about the ball, because City were getting so much joy with O’Reilly.It was a tactical masterclass from Pep at half-time. Absolutely brilliant. He got his experienced players to carry that out and free up the young kid down the left.Silva is a tactical genius. He’s the one who carries out these little things on the field that go unnoticed.OMAR GODWe don’t know how long Haaland will be out after he suffered an ankle injury but what a replacement to have.I want to focus on Marmoush’s run for his goal, it’s absolutely amazing. O’Reilly plays a high-quality pass.But Marmoush goes the opposite way to where you’d expect him to go.As a defender, they had no idea which one of the two was going to pick him up – and nobody did.Marmoush went backwards, which opened up this big space and nobody went with him. And the finish was good too.Those little darting runs he makes around the edge of the area, he’s so dangerous. Omar Marmoush made an amazing run for his strikeCity’s half-time tweak allowed Marmoush and others to get forward moreSo impressive. I love him as a player and can’t wait to see more of him.In a tactic where you’ve got Haaland and one or two others, it suits him down to the ground.Someone like Foden is in there working hard, it gives him more freedom to play closer to Haaland.But with the striker injured, Marmoush is also a ready-made replacement. I don’t care where he plays – as long as he’s on the pitch.He was outscoring Harry Kane in the first half of the Germany season, which is no mean feat.He’ll just get better, City get a lot of chances. They create a lot and he’s playing for Pep so the sky’s the limit.THE LONG HAALCity played it long, and it was slightly different to what I thought. It was Ederson into Haaland, but they did it cleverly because he should have had a first-half hat-trick.City went over Bournemouth’s midfield early on and it worked really well.They split the centre-backs on the edge of the box, Ederson gave it to one then received it and went long.So it wasn’t long straight away, it was like a one-two. Pep also told Haaland to not stay central and create an angle for Ederson.It also creates space for others joining in for the second ball. It was very direct and Haaland got a lot of joy.Ederson’s long passes worked a treat against Bournemouth’s pressHaaland looked to drift wide and take advantage of Bournemouth errorsHowever, he looks a little off at the moment, he normally puts chances away.More teams are direct now. Ederson is so good, he’s picking out a five-yard square he’s going to land the ball in.That’s where Haaland’s going to be and you can play off him there.The midfielders and attackers supporting the striker had to work their socks off. It wouldn’t have been unfair if City had been 3-1 up at half-time.NUNES GOT COOKEDHe was a real issue. He was hitting this blind ball into midfield.Lewis Cook was marking De Bruyne and bravely left him to move towards Nunes. Before he’s even completed his pass, Cook intercepts it for the Bournemouth goal.It was really poor from Nunes, but he also had the chance to make up for it afterwards by just doing a simple defender’s job.He takes a look over his shoulder, sees Kluivert and switches off.In that split second, Brooks plays the ball behind and Kluivert goes blindside of him.Matheus Nunes had a shocker as his lazy pass ended up in a Cherries goalThe midfielder, playing at right-back, couldn’t even do the defensive basicsIt’s not far, just get across and cover. It wasn’t even midfield defending, let alone proper defending. It was terrible stuff.Thankfully for Nunes, he’s got a genius manager. But I’m still not sure what he is.I don’t know if he’s a midfielder, a 10, a winger. He’s certainly not a full back. City have to address that.Tactically they’re all in the right position but it’s that instinct in those positions that’s not quite right.Gvardiol plays in a way that he can push into the number 10 position as an inverted full-back.Read More on The SunHe moved into a left centre-back position yesterday and did a brilliant job so he’s the utility defender.Go and get a right-back, Pep. I’d love to see this shape a bit more, maybe even against Man United next week. More