Henderson was released by Forest in 2014, with the club deciding against exercising an option in his two-year deal to extend it for another 12 months.
He signed with Leyton Orient, scoring eight goals in 25 games for the club.
The Nottingham Post report Henderson has travelled with the squad to Sweden, along with fellow trialists Nicky Maynard and Paul Taylor.
The fact Forest are looking again at Henderson speaks volumes to their struggles to find quality available forwards, largely due to the transfer embargo placed upon them.
Henderson netted 11 times in 49 games for the club, after signing from Millwall. He has experience at Sheffield United, Watford, Gillingham, and Reading.
He is now 33-years-old and would only be a back-up option, but even so he is not the sort of signing which is likely to get fans excited for the season ahead.