In a transfer window that's been distinctly quiet thus far, Chelsea's reported £7 million signing of Gary Cahill yesterday was a major move.
The Andre Villas-Boas reign has so far been a mixture of major highs and damaging lows, with victory over Manchester City and qualification into the Champions League knockout stages compounded by defeats to Aston Villa and QPR, as well as losses to rivals Arsenal, Manchester United and Liverpool.
Whilst the fortunes of striker Fernando Torres, as well as the future of Didier Drogba, have been key turning points in the campaign to date, it's the Blues' defensive frailties which have been an Achilles heel.
Alex has fallen out of favour under the former Porto boss, whilst David Luiz remains a worrying presence at the heart of the defence with a desire to rush forward at every opportunity.
Branislav Ivanovic has recently been injured, with the versatile defender out-of-action since coming off during the 1-1 draw against Tottenham Hotspur on December 22nd.
Taking those three out of the equation, and only club captain John Terry is left as the senior central defender at Stamford Bridge, and if the club hold serious title ambitions, strengthening in the position was key.
In Cahill, the Blues have snapped-up a bargain buy. The England international was touted for as much as £18 million in the summer, a price Harry Redknapp wasn't willing to pay to take the Bolton player to Spurs.
But, with his contract set to expire in the summer, the Trotters were forced to accept a cut-price £7 million, and Chelsea were first to act despite reported interest from Manchester United and Liverpool also.
Champions League eligibility is another major coup, and with the first leg of the club's tie against Napoli coming on February 21st, Cahill has plenty of time to learn the defensive system.
Settling in shouldn't be a problem though, because England colleagues Terry and Ashley Cole will be alongside the 26-year-old as he learns the ropes under AVB.
So, how do Chelsea catch Manchester City. Simple, by not dropping points.
True, it's much easier said than done, but if you don't concede, you can't lose. Clean sheets will be key to any possible success for the Blues this season, and taking points off their rivals is also a priority.
Manchester United at home on February 5th, City away on March 17th followed by Spurs at home on the 24th, and then Arsenal at the Emirates and Liverpool at Anfield on the 21st April and 5th May respectively are the days to look out for.
Cahill could prove to be a valuable big-game player for the Blues, and the difference between success and failure this term.
Now, if they could just add one more player. Eden Hazard anyone?