Paterson, 29, is a free agent after leaving Bristol City at the end of last season and will spend the new few days training and playing with the Boro squad in the south-west.
Warnock said: “Jamie is a lad I’ve always kept in touch with.
"It’s a good opportunity to have look at him in this environment, it’s a no-brainer really."
Paterson played over 150 times for the Robins after joining from Nottingham Forest in 2016.
The Coventry-born player started his career with Walsall before linking up with Forest - subsequently featuring for Huddersfield during a season-long loan in 2015-16.
Paterson later spent time on loan at Derby in 2019-20.
He will feature in Boro's pre-season friendly at Saltash United on Monday evening (7pm).
Boro will then face further non-league opposition in Tavistock on Wednesday before visiting Warnock's former club Plymouth Argyle on Friday.
So far this summer, Boro have made four close-season signings, bringing in keeper Joe Lumley, winger Sammy Ameobi, forward Uche Ikpeazu and former Huddersfield and Leeds United defender Lee Peltier.