The former Tottenham Hotspur and Newcastle United man explained in his BBC Sport column why the Queens Park Rangers striker is so highly rated.
Jenas, who played with Austin at QPR and knows the English forward inside out, was criticised on Twitter by some for his views on his former teammate.
The former England international has hit back at those who doubt him by using the example of Tottenham striker Harry Kane among others.
S.long cost 12mill R.McCormack cost 11million B'burn turned down 13million for Rhodes but Chaz ain't worth 15mhttps://t.co/mbSDvuoFOT— Jermaine Jenas (@jjenas8) August 21, 2015
Harry Kane's had one good season but does that mean he's not worth that kind of money then? https://t.co/Q72o43qUDn— Jermaine Jenas (@jjenas8) August 21, 2015
He scored 18 goals in a struggling side you can't under estimate that! Ur one season argument was rubbish basically. https://t.co/F2ibUxjxPc— Jermaine Jenas (@jjenas8) August 21, 2015
Earlier this week, West Ham United co-chairman David Sullivan told the Knees Up Mother Brown podcast that the club have not signed Austin due to doubts over a previous knee problem.
Austin scored 18 goals and created 23 chances in 35 Premier League appearances last season.
The Englishman had a pass accuracy of 66% and a shot accuracy of 67%, and won 86 headers, 15 dribbles and 16 tackles.
The former Burnley star has started the 2015-16 season on a positive note, scoring two goals and creating six chances in three Championship appearances.
Austin has a pass accuracy of 65% and a shot accuracy of 50%, and has won eight headers and five tackles.