Chelsea are keeping a close eye on Borussia Dortmund's young star Jude Bellingham, according to reports.Bellingham is regarded as one of the best young footballers in the world right now and recently made his debut for the England national team.Chelsea to decide between Declan Rice and Bellingham?Jude Bellingham in action for Borussia DortmundJude Bellingham joined Borussia Dortmund from Birmingham City for £25 million in the summer, rejecting Manchester United in the process. The move has been vindicated so far, with the 17-year old performing well for the Germans.A highly-touted player during his time with Birmingham City, Bellingham's performances have once again piqued the interest of top clubs, including Chelsea.There is no denying that Chelsea are interested in signing a midfielder. West Ham United star Declan Rice was heavily linked in the summer, and the former Chelsea academy player is reportedly on their radar once again.Bundesliga Debut ✅Champions League Debut ✅England U21 Debut ✅England NT 🔜Congrats to Jude Bellingham on getting his first #ThreeLions call-up! What a year it’s been so far! 🌟🏴󠁧󠁢󠁥󠁮󠁧󠁿 pic.twitter.com/6eBANSHOYF— Borussia Dortmund (@BlackYellow) November 10, 2020With the January transfer window approaching, Chelsea could make a concrete effort to sign Rice in order to shore up their midfield. Jorginho, Mateo Kovacic and N'Golo Kante are the Blues' current central midfield options, while Mason Mount is also a key player at the club.However, competition for Bellingham's signature will be fierce, with Manchester United keeping tabs on the youngster as well.Chelsea were extremely busy during the summer transfer window, bringing in German attackers Timo Werner and Kai Havertz, midfielder Hakim Ziyech, goalkeeper Edouard Mendy, left-back Ben Chilwell and center-back Thiago Silva.After a slow start to their season, Frank Lampard's side have picked up pace in recent weeks, and the addition of Mendy and Silva seems to have improved their fragile defense.17 years and 136 days old 👶Borussia Dortmund's Jude Bellingham becomes the third youngest player in England history 👏 pic.twitter.com/E4cBhlZ0yo— Goal (@goal) November 12, 2020Rice's potential transfer will add solidity to the midfield and his ability to play as a center-back could prove to be useful.The England international has made 119 appearances in all competitions for West Ham United since his debut in 2015 and played every Premier League game last season as the Hammers finished 16th.He is said to be interested in a return to Chelsea. His signing could signal the end for Jorginho, who was heavily linked with a move away in the summer.Also Read: France manager Didier Deschamps wants Olivier Giroud to resolve Chelsea situation