Like it or not, professional club football is first and foremost a business, and that fact has never been more clear than in this modern era of record-breaking revenues, skyrocketing wages, and financial fair play. While it may seem callous to so quickly turn the page on Petr Cech's illustrious career between the posts at Chelsea, it only makes sense to move forward and focus on why Chelsea made this deal and how the club benefits from selling one of the best goalkeepers in the world to its cross-town rival.

It's important to note that this deal is a bit unique in that it doesn't seem to be strictly motivated by footballing or financial reasons. Cech himself explains how owner Roman Abramovich helped Cech fulfil his desire to stay in the Premier League and play regular first team football.

"The limited playing time gave me the chance to refresh and rest mentally as well as make me realise just how much I enjoy playing football at the highest level, because I missed it badly every game day I was not involved. I have the same commitment to football, the same motivation and the same hunger for success as I had at the beginning of my career and I love the challenges brought by the top quality players you face while playing in the Premier League - simply the best and most challenging league in the world. That's why I spoke to Mr. Abramovich about me staying in the Premier League and I'd like to thank him from the bottom of my heart for his support in this matter. It means so much to me because without him Chelsea Football Club would not be where it is now. He deserves huge credit for what he has done for the club and all of us."

Based on Cech's statement, it seems like the club's decision-making deviated from the Granovskaia-Mourinho-Emenalo triumvirate that tends to conduct transfer business on behalf of the club. It also seems like the decision to sell Cech to Arsenal rather than PSG or another suitor on the contintent resulted from the strong relationship Abramovich and Cech had built over the years. Of course, Abramovich is free to do whatever he wants, as its his football club, but the deal seems to have been made, at least in part, because of personal relationships and loyalty (which again, is completely valid, but important to note).

That said, Chelsea looks to have done quite well on this deal from a business perspective.

Cech is one of the best goalkeepers in the world, but at Chelsea, he was a bit player last season due to the emergence of Thibaut Courtois. His number was called for seven Premier League matches (one of which was to replace an injured Courtois) the two Champions League matches against Maribor and the final group stage match against Sporting when Chelsea had already clinched the group, and he also got four of the six league cup matches and the two FA Cup matches.

He also had just one year remaining on his contract and turned 33 years old in May. I don't particularly think his age is a cause for concern, as he's younger than Edwin van de Sar when he joined Manchester United and Jens Lehmann when he joined Arsenal, but it's worth mentioning.

Despite Cech being relegated to the bench last season, having just one year left on his contract, and agreeing to help him stay in the Premier League (thus reducing the club's negotiating power with Arsenal over a transfer fee, as there was no competing offer from PSG or another potential suitor to legitimately use as leverage), Chelsea still managed to secure the largest-ever transfer fee for a footballer over the age of 32 AND the sixth-largest fee for a goalkeeper (as first noted by Simon Gleave at Infostrada Sports).

Through that lens, Chelsea did quite well to get £10m for Cech. As the deal was finalised prior to the 2015/16 financial year (beginning on 1 July), the entire £10m will be recorded as profit on the 2014/15 books. Additionally, Cech's £100k per week wages, at an annual cost of £5.2m, will be wiped off the 2015/16 books.

This amounts to £15.2m worth of additional spending power Chelsea has under financial fair play spread out over two years. Naturally, a portion of this will go towards procuring another backup goalkeeper, but the vast majority can be reinvested into squad to help sign players that fit into Jose Mourinho's first team plans.

As with Juan Mata, David Luiz, Romelu Lukaku and Andre Schurrle before him, if another club is offering a big transfer fee for one of Chelsea's bench players, it only makes sense to accept. Chelsea has proven time and time again that every single penny the club earns will go right back into improving the team, and with Chelsea's significant, but ultimately finite resources, shifting said resources from the bench onto the pitch will always be the best option in my eyes.

As far as the Arsenal wrinkle goes, of course, I won't be thrilled to see Cech in red, and no disrespect to a great footballer, and more importantly, a great person by all accounts, even though Arsenal is a better football club with him, Chelsea without Petr Cech is still quite a bit stronger than Arsenal with Petr Cech.

Addendum: How the deal affects Arsenal's finances

Make no mistake, this is a very good deal for Arsenal as well. Cech will reportedly earn the same £100k per week he was on at Chelsea, and the deal is either a three-year deal with an option year or a straight four-year deal. For simplicity, assuming Cech signed a straight four-year deal, he'll cost £7.7m per year on Arsenal's FFP books (£5.2m in wages plus £2.5m annually in player amortisation).

For perspective, Cech will be Arsenal's fourth most expensive player on their 2015/16 FFP books, behind Mesut Ozil (£16.3m), Alexis Sanchez (£13.8m), and Danny Welbeck (£9.2m). This is a fairly significant amount for a goalkeeper (almost 50% more than the £5.24m per year that Thibaut Courtois costs Chelsea), and while there have been concerns about how Cech will handle playing for a club that employs a high defensive line, he's a top keeper and Arsenal can definitely afford it.

As mentioned, and this could admittedly be a blue-tinted outlook, I think Arsenal needs more before they can start thinking about winning the league, but shoring up a position of need with one of the best available players is a great first step for them.