The 37-year-old, a member of New Zealand's Rugby World Cup-winning squad in 2011, has this week joined the Chiefs as a replacement player.
The former Highlanders, Reds and Rebels loose forward played for Otago in last season's Mitre 10 Cup after a four-year stint in Japan with the Canon Eagles.
A Chiefs spokesperson told Stuff he was only signed on as All Blacks cover until early February at this stage, but said it was "highly likely" he would play in Friday's pre-season match against the Blues in Waihi.
The Chiefs' All Blacks returned to training this week but none of them will play in Waihi. Their Super Rugby campaign starts against the Blues at Eden Park on January 31.
A potential return to Super Rugby would be a long shot for Thomson unless the Chiefs were to suffer injuries.
Thomson has made a remarkable return to rugby after suffering from lumbar discitis, a painful infection of the spine, while in Japan two years ago.
The injury left him bedridden, unable to walk and he was forced to spend an extended period of time away from the game completely.
Thomson did make a comeback last year in Major League Rugby with the Utah Warriors in the United States, before returning to New Zealand and linking with the Takapuna club.
"New year, new jersey," Thomson said via his personal Instagram account on Monday.
"Last week I was camping in the MacKenzie Country for some overdue kiwi-summer family time. Today I pulled on this jersey and mixed it up with 8 current @allblacks and a @superrugbynz side stacked with talent!
"It's a strange old beast this life we live, this time 2 years ago I was flat on my back in a Japanese hospital unable to walk. So never underestimate what the human body can do with a little self belief and a whole lot of hard work – persistence pays.
"Grateful for the incredible opportunity and warm welcome to this proud franchise @chiefsrugby. And as always, a massive thank you to my partner, family, friends, and rugby fans out there that keep helping to make this journey possible.⠀⠀⠀⠀⠀⠀⠀
"Day 1 done, but we're just getting started. Rent's due. Let's go to work!"