The German, 44, has out of work since being sacked by Hannover in March 2017, but has impressed the Reds hierarchy during the interview process, with the club again poised to go down the continental route following the previous appointment of Jose Morais.
Barnsley have been searching for a new boss since axing the Portugeuse immediately following the club’s relegation to League One following the 4-1 final-day loss at Derby County exactly a month ago.
The club have spoken to several other candidates, including former midfielder and ex-Peterborough manager Grant McCann and have also been linked with the likes of Wycombe Wanderers chief Gareth Ainsworth and ex-Livingston boss David Hopkin.
Frankfurt-born Stendel was placed in charge of Hannover back in April 2016, initially on a caretaker basis – his first managerial appointment.
Despite falling to keep the club in the Bundesliga, the former under-19 coach signed a two-year contract in the summer.
But he and his assistant Markus Gellhaus left in March 2017 after the club dropped out of the promotion places in the second-tier – following 13 wins and seven draws from 25 league games in charge.