The 34-year-old is out of contract at Hull this summer, and could still rejoin the Reds once the season is over.
In the meantime, the following free agents could be considered by Forest boss Aitor Karanka, should he still wish to add to his options at centre-back.
Caulker is said to have trained with Luton Town this week after being released by Queens Park Rangers in December. It's only two years ago, however, that the former England defender signed for Liverpool. The 26-year-old former Tottenham product - and Dawson teammate - could be worth a gamble on a deal to the end of the season.
Reports claimed Bassong had trials with Kilmarnock and Birmingham City in late 2017, having been freed by Norwich City earlier in the year. Another of Dawson's ex-Tottenham teammates, the 31-year-old, too, has some pedigree - further evidenced by his 15 caps for Cameroon. He has also appeared at left-back beforehand, ticking another box for Nottingham Forest who've let Armand Traore join Cardiff.
Wollscheid had his Metz deal terminated last month after failing to make a single Ligue 1 appearance following his summer move from Stoke City. The 28-year-old, who also counts Wolfsburg and Bayer Leverkusen among his former clubs, was a Premier League regular two seasons ago and won two caps for Germany in 2013. He's arguably the best Forest could get right now.
Should Nottingham Forest consider any of the above as short-term alternatives to the former Tottenham Hotspur defender?