The Blades have eight players in the final months of their current deals while the Terriers have six men whose contracts run out at the end of June.
There is the option for a further year with two of Huddersfield's out-of-contract stars while the other four are set to leave the club if new deals cannot be agreed.
Although, there remains plenty of time for discussions to be held.
None of the Blades' out-of-contract players have options to extend. The club may decide to release some or all of the crop of squad members whose deals expire in the summer but that remains to be seen.
Contract extensions can be agreed, signed and announced at any time throughout the season and are not restricted to the summer and window transfer windows.
Below, is every Huddersfield and Sheffield United player in the final year of their contract according to transfermarkt.co.uk.

. Billy Sharp
OUT OF CONTRACT: Billy Sharp is one of eight Sheffield United players who is out of contract this summer, while Huddersfield have six players whose deals expire in the summer. Picture: Getty Images Photo: Getty Images

. Lys Mousset
Lys Mousset (Sheffield United) - The 25-year-old joined the Blades in 2019 and has played 53 times for the club, scoring nine goals. Photo: Getty Images

. Ben Osborn
Ben Osborn (Sheffield United) - The utility man signed for the Blades in 2019 and has played 67 times for the club. Photo: Getty Images

. Jack Robinson
Jack Robinson (Sheffield United) - The former Liverpool and Huddersfield Town player joined the Blades in January of 2020 from Nottingham Forest. Photo: Getty Images

1. Lys Mousset
Lys Mousset (Sheffield United) - The 25-year-old joined the Blades in 2019 and has played 53 times for the club, scoring nine goals. Photo: Getty Images

2. Ben Osborn
Ben Osborn (Sheffield United) - The utility man signed for the Blades in 2019 and has played 67 times for the club. Photo: Getty Images

3. Jack Robinson
Jack Robinson (Sheffield United) - The former Liverpool and Huddersfield Town player joined the Blades in January of 2020 from Nottingham Forest. Photo: Getty Images

4. David McGoldrick
David McGoldrick (Sheffield United) - The centre forward has been at Bramall Lane since the summer of 2018. He has made 129 appearances for the club, scoring 30 goals. Photo: Getty Images