Sometimes a transfer just makes sense; other times it can be more forced. Some of the top clubs in Europe have been busy in January, but here are 10 deals that have not been talked about as much as they perhaps should be.
Ross Barkley - Everton to Manchester City
The English midfielder is going to be one of the best in the Premier League in the coming years and with Yaya Toure likely to depart this summer, a gap will open up. Barkley's drive and dynamism from midfield will put him on top of many shopping lists, but City have the financial muscle to make it happen. If the club are willing to spend £54 million on Kevin De Bruyne, then adding Barkley is a no-brainer.
Hector Bellerin - Arsenal to Barcelona
Barcelona love to buy back players who have been at their academy and know how to play the Catalan way, so it's surprisingly they have not been banging on the Arsenal door to bring back Bellerin. The right-back may have developed in London, but Barca surely see him as the eventual replacement for Dani Alves don't they?
Harry Kane - Tottenham to Manchester United
Stop us if you've heard this one: the best English striker of his generation moving to one of the world's biggest clubs and becoming a legend. The storyline writes itself for Kane to replace Wayne Rooney but a recently signed new contract means he won't come cheap.
Philippe Coutinho - Liverpool to Real Madrid
With their famed BBC [Bale, Benzema, Cristiano] trio under pressure at the Bernabeu, Madrid may look to expand their horizons and bringing in Coutinho would be a masterstroke. Isco and Jese have hardly set the world alight, so the Brazilian seems a simple addition and Liverpool would be able to use some of the cash to revive their flagging squad.
Aymeric Laporte - Athletic Bilbao to Arsenal
The 21-year-old defender is one of most highly rated youngsters in the game and won't come cheap, but he could be the cornerstone that Arsenal build their defence around for the next decade. The Frenchman would surely jump at the chance to learn under Arsene Wenger, and could easily replace Per Mertesacker on current form, but would they shell out for a defender?
Gonzalo Higuain - Napoli to Liverpool
Liverpool need a goal scorer and they don't come much better than Higuain. The Argentine striker would thrive in the Premier League and is a much better option for Jurgen Klopp than Christian Benteke as he could also support a main striker from the wings.
Marco Reus - Dortmund to Bayern Munich
You've seen the story before: Bayern buy their rival's best player (such as Mario Gotze and Robert Lewandowski) and strengthen their squad while ruining the hopes of the only other team who could challenge them in Germany. Reus would not come cheap, but with Franck Ribery and Arjen Robben needing to be replaced, he would fit the bill nicely.
Mario Gotze - Bayern Munich to PSG
It doesn't always work out though. Despite scoring the winner in the World Cup final for Germany, Gotze hasn't really lived up to expectations in Munich and may be keen to move on. With Zlatan Ibrahimovic set to depart this summer, PSG will be on the lookout for a new striker and Gotze's style would certainly suit Ligue 1.
Marquinhos - PSG to Chelsea
Chelsea have tried and failed to sign Everton's John Stones, but they might not be aware that a player of similar potential (and one who plays in the same position) is not getting much game time in Paris. Just eight starts in Ligue 1 this season for Marquinhos means the Brazilian defender is looking elsewhere, and Stamford Bridge would seem to be the ideal destination for him.
Gianluigi Donnarumma - Milan to Juventus
If Juventus and Italy legend Gianluigi Buffon calls you "a top goalkeeper" then you have to be good, and the 16-year-old Donnarumma has proven as much this season so far with Milan. Given that Buffon has just turned 38, Juventus would be crazy not to try to lock the youngster down and, in doing so, secure their No. 1 spot for possibly the next two decades.