The T20 Blast is back albeit with a lot of intriguing questions and youngsters set for a breakout phase in the tournament. The English international season adds another layer of intrigue with superstars Jos Buttler, Jason Roy and Adil Rashid among a fair few to be out on international duty.But their unavailability opens a door of opportunity for a few talented youngsters and veterans to prove their point in one of the best T20 competitions in the world. Leading upto the return of the T20 Blast, here's how the two groups stand!North Group: Amid the middle-muddle, can Surrey sustain its form?The North Group has, at the same time, been a one-horse race and quite competitive. While a star-studded Surrey has blown away opponents with their might, the likes of Essex, Gloucestershire and Sussex are all in the mix for a place in the top four.But here's where it gets interesting. Jason Roy, Sam Curran and Reece Topley are unavailable for Surrey, leaving them short on star-power although they still have Kieron Pollard in their ranks. But against teams that remain at full-strength, Surrey will need to play out of their skins to retain their unbeaten status.Sussex is undoubtedly the team to watch out for and for good reason. While Mohammad Rizwan is back from international duty, the arrival of Rashid Khan adds much-needed strength to their bowling attack. With three wins in eight games and in desperate need of a couple of wins, Sussex is one to watch out for in this tournament from here on.South Group: Lancs and Yorks among competitors for a top-four finishWhile the North Group has been fairly competitive, the South Group has been a level above. Nottinghamshire, a team that boasts of a top-four of Clarke, Hales, Duckett and Moores, is currently placed outside the top-four. While the likes of Derbyshire and Warwickshire have seemingly punched above their weight, it's been Lancashire who has emerged as the favourites to top the table. Although they will also be missing Liam Livingstone, Phil Salt and Luke Wood, Lancs will bank on star recruit Tim David to continue his fine form.The T20 Blast is still at the halfway point with a whole lot to play for! Who will step up for their respective teams as we head into the business end of the tournament? Only time will tell!