Who will pull off the eye-catching deals and who will take a gamble are the questions that dominate the football landscape, while players keen to relaunch their careers look to stir things up at a new destination. This winter represents another crucial chance for teams to shuffle the pack, and FIFA.com now looks back at all the major deals over the last couple of weeks.
Since leaving Inter Milan in 2011, Samuel Eto'o has been playing more or less for pleasure alone, having stacked up every title going during his time with I Nerazzurri and Barcelona before that. Now 34, the Cameroonian striker is returning to Italy to join Sampdoria, following spells with Anzhi Makhachkala, Chelsea and, most recently, Everton.
While Odegaard is savouring the dawn of his career, Uruguayan midfielder Sebastian Eguren is close to the twilight of his own. The 34-year-old has spent time in six different leagues and has now left Brazilian side Palmeiras for the team where he first turned professional, Montevideo Wanderers. As for Dario Conca, the Argentinian midfielder is also returning to more familiar terrain after swapping Fluminense for Shanghai SIPG in China PR, where he turned out for Guangzhou Evergrande between 2011 and 2013.
In contrast, Alberto Gilardino has departed Guangzhou after less than a year, the Italian forward bringing his finishing skills back to Fiorentina following an earlier spell there from 2008 to 2012. Gilardino's compatriot Salvatore Bocchetti has touched back down on Italian soil as well, with the defender joining AC Milan on loan from Spartak Moscow. Meanwhile, Ivorian forward Didier Ya Konan has renewed his ties with Hannover after contesting just a handful of games for Al Ittihad since he left the Bundesliga outfit last summer. And Sacha Kljestan is back in his native USA five years on from moving to Anderlecht, the midfielder having penned a deal with New York Red Bulls.
One of the bight new hopes of Dutch football when he burst on the scene with Feyenoord in 2005, Royston Drenthe struggled to make an impact after subsequently being picked up by Real Madrid. His career then took him to Hercules Alicante, Everton, Alania Vladikavkaz, Reading and Sheffield Wednesday, and, at 27, the winger is now making a fresh start with Erciyespor in Turkey. His story will no doubt sound familiar to Marko Marin, the one-time German wunderkind having lost his way since departing Werder Bremen in 2012. His stays with Chelsea, Sevilla and Fiorentina were less than convincing, so he will be anxious to bounce back with new employers Anderlecht.
Elsewhere, Portuguese marksman Hugo Almeida will aim to rediscover the form that made him a success at Porto and Bremen with Russian club Kuban Krasnodar, having failed to notch a single goal during his six months with Cesena. In Italy, Uruguay's Cristian Rodriguez and Portugal's Silvestre Varela will be similarly eager to make a splash at Parma, opting to help the side battle against relegation after leaving respective former clubs Atletico Madrid and Porto.
Lastly, Brazilian defender Gabriel Paulista has bolstered Arsenal's options at the back after serving Villarreal with distinction since 2013. He thus leaves a team aiming to play in the UEFA Champions League next season for one through to the knockout stages of the competition this term.
Players to follow
The Uruguay side that reached the final of the FIFA U-20 World Cup Turkey 2013 was brimming with exciting youngsters, but the players themselves singled out Giorgian de Arrascaeta as the most gifted in their ranks. The attacking midfielder has since gone on to represent Uruguay's senior team and is now beginning a new challenge in the club realm after swapping boyhood club Defensor Sporting for Cruzeiro. There, he will try to fill the void left by Everton Ribeiro and Lucas Silva, who have started new chapters at Al-Ahli Dubai and Real Madrid respectively.
4 – The number of times Joel Campbell has been loaned out in the four years since he signed for Arsenal. The Costa Rica forward has shone for his national side and impressed on his loan spells at Lorient, Real Betis and Olympiacos, but he has still not managed to carve out a first-team spot in north London. The Gunners clearly retain faith in his potential, though, opting to loan rather than sell him to Villarreal.
What they said
"He's a good player. He's a young boy who can still grow. He's only 16 and he has a big future ahead of him. We need to give him the time to learn and make better decisions, but I see a lot of talent in this player and a very good left foot," Madrid forward Cristiano Ronaldo on Martin Odegaard.