UK

In England, Alex Robertson was an unused sub once for Manchester City. In the second tier, Kenny Dougall made three appearances for Blackpool, Nicholas Bilokapic was an unused sub four times for Huddersfield Town, and Callum Elder made one sub appearance for Hull City. Elsewhere, Riley McGree scored once across four appearances for Middlesbrough, Dean Bouzanis was an unused sub four times for Reading FC, and Harry Souttar played four full games for Stoke City. Bailey Wright made two appearances for Sunderland whilst Tom Rogic scored once and provided two assists across five appearances for West Bromwich Albion.

In the third tier, Gethin Jones picked up one assist across three appearances for Bolton Wanderers, whilst his teammate Jack Iredale started four times for the club. Cameron Burgess scored once across five full games for Ipswich Town, whilst teammate Tete Yengi returned to the club after a loan spell in Finland. Caleb Watts picked up one assist across four appearances for Morecambe FC, whilst Ashley Maynard-Brewer played four full games for Charlton Athletic.

In the fourth tier, Lachlan Brook scored once across three appearances for Crewe Alexandra, whilst Jacob Chapman played one full game for Salford City. Manager Jon Brady guided Northampton Town to only one win from four in December, with his team sitting third on the table. In the fifth tier, Reagan Ogle played two full games for Scunthorpe United.

In the lower leagues, Joel Rollinson was an unused sub once for sixth-tier Hungerford Town. Elsewhere in the sixth tier, Lewis Miccio played one full game for Oxford City, whilst Callum Kealy scored four goals across five starts for Worthing FC. In the seventh tier, Matthew Macarthur started once for Margate FC.

In the youth leagues, Shae Cahill picked up an assist on his only sub appearance for Everton U18, Lucas Scicluna played one full game for Wolverhampton U18, an 8-0 loss, and Aidan Coyne played two full games for Watford U21.

In Scotland, Aaron Mooy scored twice and picked up one assist across four appearances for Celtic. Aziz Behich picked up an assist on his only start for Dundee United, whilst his teammate Mark Birighitti played two full games for the club. Cameron Devlin and Kye Rowles both featured for Hearts. Devlin picked up two assists across three appearances, whilst Rowles started twice. Teammate Nathaniel Atkinson was an unused sub three times for the club. Elsewhere in the first tier, Phillip Cancar was an unused sub three times for Livingston, whilst Ryan McGowan started twice for St. Johnstone. Ryan Strain started twice for St. Mirren whilst his teammate Keanu Baccus played two full games for the club.

Manager Ange Postecoglou had a perfect month at Celtic, leading them to four wins from four as they currently sit nine points clear atop the Scottish Premiership table.

In the Scottish third tier, Murray Miller made four appearances for Alloa Athletic, whilst Aaron Lennox was an unused sub three times for Montrose FC.

In Wales, Harry Arnison started four times for Aberystwyth Town, whilst Joe Faux scored once across four full games for Caernarfon.

EUROPE

In Belgium, Jason Davidson played one full game for KAS Eupen, whilst his teammate James Jeggo also played one full game for the club.

In Bosnia-Herzegovina, Ante Bakmaz left second-tier side FK Buducnost Banovci after his contract ended.

In Croatia, Deni Juric commenced a loan spell at HNK Rijeka. In the second tier, Marc Tokich played one full game for Bijelo Brdo, whilst his teammate Doni Grdic also played one full game for the club. In the youth leagues, Gabriel Popovic started once for NK Rudes U19, whilst Tomislav Glavan started once for NK Istra 1961 Youth.

In Cyprus, Yanni Delengas played one full game for second tier side Alki Oroklini, where his side lost 8-1. Abraham Majok picked up one assist across three starts for Anagennisi Derynias. In the third tier, Jake Taylor-Mountford, Dimitri Kostopoulos, and Lachlan Sepping all featured for APEA Akrotiri. Taylor-Mountford started four times, Kostopoulos made two sub appearances, and Sepping made four sub appearances. The trio are coached by Perry Moustakas, who led the club to three wins from four in December, and they currently sit fourth on the table.

In France, Troyes manager Patrick Kisnorbo oversaw one draw in December, with his side currently sitting thirteenth on the table. In the second tier, Alex Gersbach played two full games for second-tier side Grenoble. In the fourth tier, Yaya Dukuly made one sub appearance for Reims II.

In Germany, Jacob Italiano made one sub appearance for fourth-tier side Borussia Monchengladbach II. In the fifth tier, Mark Rizoski made one sub appearance for BCV Glesch-Paffendorf, whilst Oliver Yates played one full game for FC Pesch. Elsewhere in the fifth tier, Nicholas Simpson started once for Fortuna Koln II, whilst Jamie Percevski played one full game for Viktoria Arnoldsweiler. In the youth leagues, Christian Naveen made one sub appearance for 1860 Munich U19.

In Gibraltar, Santino Swanson Manuel made one sub appearance for Lynx FC.

In Greece, Apostolos Stamatelopoulos started twice for PAS Giannina. In the second tier, Charalampos Stamboulidis was an unused sub four times for Veria NPS. In the youth leagues, Dimitrios Valkanis, the son of former Adelaide United and Melbourne City manager Michael Valkanis, played one full game for AEK Youth.

In Iceland, Joey Gibbs signed for UMF Stjarnan.

In Israel, Nikita Rukavytsya scored once across three sub appearances for Maccabi Haifa FC.

In the Italian Serie B, Fran Karacic played three full games for Brescia, whilst Alessandro Circati was an unused sub five times for Parma. In the fourth tier, Thomas Galletti played three full games for ASD Salsomaggiore. In the youth leagues, Jahce Novello picked up one assist across three appearances for Cosenza Youth, whilst Jason Vescan-Kodor scored twice and picked up an assist across three appearances for Lecce U18.

In Malta, Charles Lokolingoy scored once across three full games for Zebbug Rangers. In the second tier, Samuel Vella played one full game for Swieqi FC.

In the Netherlands, Dylan Ryan was an unused sub twice for second-tier side Den Bosch, whilst Joshua Rawlins played one full game for FC Utrecht II.

In Portugal, Brooklyn Barataud played three full games for fourth-tier side SC Olhanese. In the youth leagues, Paul Jr Okon-Engstler scored once across three starts for Benfica U18, Jaden Gasking made three appearances for Boavista F.C. U19, and Ryan Teague started twice for Famalicao U23.

In Spain, Max Ogawa started once for fifth-tier side CD Torrijos.

ASIA

In Hong Kong, Henry Moore picked up one assist across two appearances for Hong Kong FC. In the second tier, Brett Warning played one full game for Happy Valley.

In India, Brendan Hamill played four full games for ATK Mohun Bagan, whilst teammate Dimi Petratos scored two goals and provided one assist across five full games for the club. Aleksandar Jovanovic started four times for Bengaluru, Jordan O'Doherty started twice for East Bengal, and Joel Chianese scored twice across four appearances for Hyderabad. Dylan Fox signed for Jamshedpur, whilst his new teammate Harrison Sawyer made three sub appearances for the club. Elsewhere, Apostolos Giannou scored once across four sub appearances for Kerala Blasters, Rostyn Griffiths made two appearances for Mumbai City, and Aaron Evans scored once across five appearances for NorthEast United. Finally, Osama Malik started four times for Odisha.

In Japan, Mitch Duke signed for second-tier side Machida Zelvia.

In Singapore, Obren Kljajic signed for Lion City Sailors U21.

In Thailand, manager Aurelio Vidmar resigned from his role at Bangkok United. In the second tier, Carlos Stack was released by Krabi FC.

NORTH AMERICA

In Canada, Jesse Daley signed for Calgary FC.

In the American third tier, Zaydan Bello signed for Minnesota United 2.

Most of the information throughout this article would not have been possible without the work of Damian Davies.

You can follow Christian Marchetti on Twitter @ChristianM29, or on Instagram @christianmarchetti29.