Luis Diaz to Liverpool. Dusan Vlahovic to Juventus. Ferran Torres to Barcelona. Robin Gosens to Inter. Julian Alvarez to Manchester City. These are five of the biggest deals in the transfer window that just closed... and, generally, five moves that were hailed as good business.

Time will tell, of course, but when you evaluate the impact these guys have at their new clubs (Alvarez won't be joining until next season), there's a common thread you may want consider, one that often gets overlooked: the impact their arrival has on players already at those clubs and, in particular, those whose contracts are counting down towards free agency. It's not the main reason these transfers took place, but it's a factor that is as important as ever right now particularly in terms of timing, and, you imagine, contributed to their signings.

We're talking about leverage and, perhaps, Luis Diaz's arrival on Merseyside from Porto is the best example.

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Diaz is 25 and cost Liverpool some £37m ($50m), rising to a potential £49m ($66m) with bonuses. He has been a standout performer for Porto, particularly in the Champions League, but at first glance it may seem a steep price. He's the eighth-most expensive player in Liverpool history (and if he meets his bonuses, he'll be fifth-most expensive) and yet, on paper, he's the fifth-choice forward after Sadio Mane, Mohamed Salah, Diogo Jota and Roberto Firmino. Depth is important, but Liverpool do not have unlimited resources -- they also have Divock Origi and Takumi Minamino -- so why invest in a forward and not, say, another central midfielder? Especially since they'll need to find the money to extend the contracts of Mane, Salah and Firmino, all of whom are set to become free agents at the end of next season?

The answer is in that last question. You don't want to go into a contract negotiation feeling like you have no choice but to extend a deal (or, worse, falling prey to the "Give him what he wants!" crowd). I've made the point before that Liverpool should extend Salah and Mane and, though he has been slowed by injury, Firmino too, but only at a certain price. From Liverpool's perspective, that price just got a little bit lower with Diaz coming in, which allows them to play that little bit more hardball at the negotiating table.

In short, securing Diaz now means that Liverpool are less likely to be held to ransom if Mane or Salah refuse to extend and force a deal next summer (or, worse, sail towards free agency), making the club scramble for a replacement. Is there a downside? Sure, there always is. Maybe Diaz turns out to be a bust and never settles. That said, any signing comes with risk, and that risk is mitigated by the fact that the final verdict on Diaz won't come until next season, by which point they will likely have reached a resolution, one way or another, with Mane or Salah.

Inter's deal for Gosens is along the same lines, only more so. They already have a top-notch left-wingback, Ivan Perisic, who is having a tremendous season, except Perisic just turned 33, becomes a free agent in June and is on a hefty wage. Inter are open to keeping him because he's fit and productive, but only at a certain price and for a certain number of years. With Gosens in town, Perisic's bargaining power diminishes significantly; what's more, Gosens is six years younger than Perisic and makes a little more than half as much in wages. Oh, and because it's technically an 18-month loan with an obligation to buy later, they don't need to start paying for him until 2023.

Contract extensions may not have been the main drivers of the other deals, but their impact is significant.

A major side effect of Barcelona securing Ferran Torres from Manchester City is that they can play hardball Ousmane Dembele. The Spanish international is a versatile player, but Torres has mostly played wide on the right with Spain and in his three appearances with Barcelona thus far. And while it looks like the ploy won't work -- Dembele has thus far rejected Barcelona's offers -- that part has more to do with the fact that he is on such a massive contract that it makes more sense for him to test the waters in free agency.

Consider, too, the impact of Vlahovic on the futures of Paulo Dybala (who is a free agent in June) and Alvaro Morata (Juve will need to decide whether to make his loan from Atletico Madrid permanent at the end of this season, as well as give him a new contract). Dybala and Morata turn 29 and 30 next season and are both earning significant money. Without Vlahovic, the pressure to keep them around would be far greater. Now, if one or the other or both end up staying, you presume it will be at a number with which the club is comfortable.

Then there's the case of Julian Alvarez. Manchester City signed the Argentina forward from River Plate for $20 million, but will leave him in Buenos Aires on loan until the summer. He just turned 22 and scored 22 goals in all competitions in 2021. He has been used mainly as a central striker, but can also operate out wide. City arguably haven't played with a genuine center-forward for the past 18 months (and it hasn't really affected their success), but they were in the market for Harry Kane last summer and, you'd imagine, they'll pursue Erling Haaland this summer.

Right now, Alvarez isn't in the same bracket as those two, obviously, but if they need a cheaper alternative, he fits the bill. And his versatility, crucially, impacts City's attitude towards the three players whose future they will need to sort out in the next few months, as Raheem Sterling, Gabriel Jesus and Riyad Mahrez are all out of contract in June, 2023. We know City aren't short of cash, but we also know they don't like to give huge contract extensions that run beyond a player's 30th birthday (just ask Kevin De Bruyne, who got a hefty bump, but only a two-year extension). Mahrez turns 31 next week, Sterling is 27. Again, City now have that little bit extra leverage with Alvarez on board.

Remember: we're not talking about guarantees here. Any of the players cited above could turn into mega-busts, and the sides who signed them could end up with egg on their face. We're talking about playing percentages, assessing pros and cons and evaluating risk. And among the pros, doubtless, is the impact it has on long-term personnel decisions of the sort that tie up huge amounts of cash.