The term "free agent" is used in football to address players who are not attached to any club. A player becomes a free agent after the expiration of their contract or in some cases, after the termination of their contract.With the January 2023 transfer window set to open in a few days, clubs will have the opportunity to bolster their squad for the remainder of the season.The winter transfer market also allows players who are without a club to get snapped up by clubs in need of their services mid-season.Without further ado, here's a look at four high-profile free agents at the moment.#4 Danny DrinkwaterDanny Drinkwater last played for Reading FcFormer Leicester City midfielder Danny Drinkwater is a player with an impressive CV but is currently a free agent. The 2016 Premier League winner has been a free agent since June 2022 following the expiration of his contract with Chelsea.The 32-year-old joined the west London club in 2017, but never got to become a regular at Stamford Bridge. He made just 23 appearances for the Blues during his five years at the club.Drinkwater was also shipped out on multiple loans while at the club. He had stints at Burnley, Aston Villa and Turkish outfit, Kasimpasa. His last loan spell before becoming a free agent was with Championship side Reading FC, where he made 34 appearances across competitions in the 2021-22 season.#3 Daley BlindNetherlands v Argentina: Quarter Final - FIFA World Cup Qatar 2022Dutch left-back Daley Blind recently became a free agent following the mutual termination of his contract with Ajax. The 32-year-old contract was scheduled to expire next summer, but both parties decided to part ways six months earlier.Blind had two spells with the Amsterdam club. He made his Ajax debut in 2008, before leaving to join Manchester United in 2014. After a four-year spell in England, he returned to his boyhood club and was a key member of the team, helping them win three Eredivisie titles.Fabrizio Romano@FabrizioRomanoDaley Blind contract has been officially rescinded. Dutch defender leaves Ajax as he’s now available as free agent #AjaxRoyal Antwerp, keen on signing Blind.330141451Daley Blind contract has been officially rescinded. Dutch defender leaves Ajax as he’s now available as free agent 🚨⚪️🔴🇳🇱 #AjaxRoyal Antwerp, keen on signing Blind. https://t.co/52OXggO9QVHe made a total of 333 appearances for Ajax across both spells, recording 13 goals and 21 assists. At 32, Blind is still very likely to be snapped up by one of the biggest clubs across Europe in January.He was part of the Netherlands squad for the 2022 World Cup. He scored a goal and provided an assist in five appearances in the tournament.#2 IscoIsco will be in search of a new club in the January transfer windowAnother high-profile player who is currently a free agent and will be looking for a club in the January transfer window is Isco. The former Real Madrid attacker left Los Blancos last summer and joined Sevilla on a two-year-deal.But less than five months after joining Los Nervionenses, his contract was terminated by mutual consent. According to Sevilla coach Jorge Sampaoli, the 30-year-old did not meet the club's expectations as seen in the Daily Mail.Isco is one of the most experienced and talented free agents at the moment. He has made a mammoth 353 appearances for the club, scoring 53 goals and giving 56 assists, winning four UEFA Champions League titles and three La Liga titles.#1 Cristiano RonaldoMorocco v Portugal: Quarter Final - FIFA World Cup Qatar 2022Five-time Ballon d'Or winner Cristiano Ronaldo is currently the biggest high-profile free agent in football at the moment.The Portuguese ace had his contract terminated by mutual consent with Manchester United after a controversial interview with British broadcaster Piers Morgan. The 37-year-old openly criticized the club's ownership, a couple of former teammates and manager Erik ten Hag.Ronaldo has been heavily linked with a January move to Saudi Arabia club Al-Nassr. According to transfer expert Fabrizio Romano, the Saudi club is offering the former Manchester United forward a contract worth a whopping €200 million per season.Fabrizio Romano@FabrizioRomanoAl Nassr have confirmed to Cristiano Ronaldo’s camp their intention to push and insist in the next days. The bid until June 2025 is still valid on the table, no plan to give up. #transfersCristiano will decide his future in the next days, after waiting for European clubs.699054394Al Nassr have confirmed to Cristiano Ronaldo’s camp their intention to push and insist in the next days. The bid until June 2025 is still valid on the table, no plan to give up. 🇸🇦 #transfersCristiano will decide his future in the next days, after waiting for European clubs. https://t.co/smlsJcqObk