Now that Chelsea have announced thesigning of Pedro, the complexion of theirattacking midfield is looking much different.The role of Oscar in Jose Mourinho's team looks even more so.Pedro's transfer doesn't immediately transform Chelsea's early-season fortunes, yet there is a feeling it has helped turn the tide.From the negative headlines this past or week or sopoor form and issues of a medical naturethe Spaniard's capture has the potential to rejuvenate a Chelsea attack that has been lagging since the start of the season.Indeed, Chelsea's problems in that regard stretch further back than just a disappointing past few weeks.We saw at stages in the second half of 2014/15 that Chelsea's attacking options were few. Outside of Eden Hazard and Diego Costa, no player found himself in double figures for goals scored; there was also an overreliance on a select group of players that included Oscar.The problems came when Oscar's form hit the traditional post-Christmas slump. As his influenced waned, the need for Hazard to be the creative force in the final third grew.With momentum behind him, the Belgian delivered. In the beginning stages of 2015/16, the landscape has proved much different.Teams have focused their attentions on the threat Hazard can possess, overloading their defensive commitments to null his influence.In turn, Chelsea has created little in front of goal, and it has developed into a major concern.Given the width he can provide Chelsea's attack on the right (or left, given his ability with either foot), Pedro seems to be a smart buy.The Spaniard is much more than an extra body to make up the numbers; he's a very real option for Jose Mourinho, and his presence allows Chelsea to adapt.If we look at the tried and tested 4-2-3-1 setup that delivered Chelsea the Premier League title last term, it makes sense to maintain Oscar in the No. 10 role, where he has impressed so much when on form.Oscar is creative, has the knack for scoring key goals in matchesthink the opener against QPR at Stamford Bridge last seasonand with his work rate is vital in pressing teams high up the pitch.We've seen on plenty of occasions when Oscar's pressure in the opposition half has helped create goals, while he finds gaps to play off his teammates and score himself.Against West Ham Untied in November 2013, his link-up play with Hazard was exceptional, with the move ending in the Brazilian putting Chelsea 2-0 in front.He was particularly effective that night at Upton Park, also winning the penalty that Frank Lampard dispatched to put Chelsea in front before scoring himself.What the signing of Pedro has given Chelsea now, however, is the option to switch systems and utilise the likes of Oscar in a different role to what we're used to.And it could be the making of him at Stamford Bridge, elevating him to the status Hazard enjoys.In Jose Mourinho's first spell as Chelsea boss, it was the 4-3-3 that saw his team dominate the Premier League in 2004/05.With Claude Makelele the holding midfielder, Chelsea flourished with Lampard and any of Eidur Gudjohnsen, Tiago or Joe Cole at times playing off him.A narrow midfield would have been an issue, but the width was supplied by Arjen Robben and Damien Duff, feeding Didier Drogba as the lone striker.The result was some of the finest attacking football Chelsea played under their current manager. It was fluid, threatening and had an end product.Swap Robben and Duff for Hazard and Pedro in the modern era, with Diego Costa up front, and there's a similar feel. In the central-midfield area, Matic would be the physical defensive presence, with Cesc Fabregas and Oscar pulling the strings.There isn't a like-for-like replacement for Lampard, yet the model doesn't demand there be one. What Chelsea would lack in not having a prolific goalscoring midfielder, they would make up for in creativity.That's been the issue for Chelsea since Christmas. Among other things, they haven't been consistent in creating enough goalscoring opportunities and stretching opposition defences.Against the bigger teams, they have been easier to contain.With the Premier League title secured for 2014/15, that doesn't matter. Chelsea were methodical in the way they went about their business when it mattered and got the results they needed.It's a different story now, though. Things need to change, to be adapted in order to get the better of teams far more convincingly.Such is the quality in Chelsea's squad, they will always win more matches than they lose. With stronger title rivals this time out, it may not be enough to finish on top again, however.Chelsea were so fluid in the early stages of the previous campaign that many got carried away with how far Mourinho could actually take this teamthis writer included.There was talk of it being an invincible campaign, a season that could end with treble success.Time soon told us that talk was premature; not because the manager lacked the nous or because his players weren't good enough. It came down to not having the right personnel to adapt when times called for it.Adopting a 4-3-3 can raise Oscar's opportunities for operating more centrally in an area of the pitch where he has been most effective in a Chelsea shirt.When Chelsea were at their free-flowing best last season, the Brazilian and Fabregas were linking up to good effect.Purely from a footballing spectacle, it was thrilling. They seemed to have an instant understanding of how each other operated, almost telepathically interchanging and filling space vacated by the other.That made Fabregas difficult to pick up, so it came as no shock when he was hitting double figures for assists before Christmas.In fact, near the end of the season, we saw it again when Oscar was introduced as a substitute against QPR at Loftus Road.That game had been particularly frustrating for Chelsea against a Rangers side determined to end the game with anything but a defeat.Oscar's introduction influenced Fabregas, who eventually scored the winner.When it comes to his ability on the ball, Oscar isn't as cute as Fabregas in that regard. Yet what he lacks in possession he makes up for with that ability to press and win the ball back.Fabregas can't be faulted for his endeavour, but he isn't as effective when it comes to his defensive qualities.With Oscar sitting deeper to play alongside him, he needn't be anyhow. Oscar may be slight of frame, but we shouldn't let that deceive us.When Mourinho promoted him over Juan Mata two years ago, it was as much for those defensive qualities as it was his creativity. After all, teams can have too much of a good thing, so with the likes of Hazard and others offering qualities elsewhere in the team, it was Oscar who got the nod.Adjusting to a 4-3-3 doesn't edge out Willian, either.As Chelsea legend Pat Nevintold Bleacher Report this week, Oscar's compatriot has often operated more productively playing more centrally than the right side of an attacking three where we're used to seeing him.Now that Pedro is expected to take up that role, it frees Willian to return and join the likes of Oscar and Fabregas in the middle.Playing that trio together wouldn't be an option, but Willian can help Oscar by simply playing games and being there.With the burnout that has hindered Oscar, rotation is key in preserving him. Willian has a big role to play in that, as he would in Chelsea's overall dynamic, given how versatile he has proved himself.Pedro's arrival has been dressed up as a threat to a few Chelsea players, but it shouldn't be viewed in that way. For Oscar especially, it may well be the trigger to elevate him to the next level in his Chelsea career.Garry Hayes is Bleacher Report's lead Chelsea correspondent. All quotes were obtained firsthand unless otherwise noted. Follow him on Twitter @garryhayes Click here to read full news..