Middendorp failed to deliver the 2019/20 Absa Premiership title to Naturena despite leading Chiefs in pole position for all of 28 rounds, only to lose it to Mamelodi Sundowns on the final day of the season.
This follows Amakhosi's devastating 2018/19 campaign in which they also suffered heartbreak by dropping out of the top eight on the final matchday, before becoming the first top flight club to lose the Nedbank Cup final to lower tier opponents TS Galaxy.
The 61-year-old penned a two-and-a-half-year deal in December 2018 as he took over from Italian mentor Giovanni Solinas, who was also sacked over the team's poor performance.
However, the club has confirmed that he will not see out the remaining year on his contract as the club looks to replace him ahead of the 2020/21 campaign, which is scheduled to kick-off next month.
After 60 matches at the helm during his second stint with tThe Glamour Boys, Middendorp managed 31 wins, 12 draws and 17 losses in all competitions, with no silverware obtained.
1997/98 - Ted Dumitru (Sundowns) - The Romanian replaced Reinhard Fabisch and guided them to their first PSL title. Sundowns suffered just four defeats, finishing on 68 points.
1998/99 - Ted Dumitru (Sundowns) - Dumitru won The Brazilians' second successive PSL title in a season that was decided on GD of +5. Sundowns and Chiefs finished on 75 points.
1999/00 - Paul Dolezar (Sundowns) - Born in Yugoslavia, raised in France, Serbian citizenship, Dolezar's arrival helped Downs complete a hat-trick of league titles with 75 points.
2002/03 - Roy Barreto (Pirates, bottom left) - Zim-born Barreto won the league but was then escorted out of Chatsworth Stadium under heavy security – one of the reasons he quit.
2003/04 - Ted Dumitru (Chiefs) - The Romanian was back at it again as he led Amakhosi to their first ever PSL-era title. They finished on 63 points.
2004/05 - Ted Dumitru (Chiefs) - This time 62 points were enough for the Glamour Boys to finish as champions. He claims he left to pursue a research programme in local soccer.
2005/06 - Miguel Gamondi (Sundowns) - The Argentinean won the league as a joint-coach alongside Neil Tovey. He arrived in South Africa in 2005 as an assistant to Angel Cappa.
2010/11 - Ruud Krol (Pirates) - This was the Buccaneers' third PSL title. The Dutch legend led Pirates to a historic treble but ended up leaving and was replaced by Julio Leal.
2011/12 - Augusto Palacios - (Pirates) - The Peruvian mentor took charge of the Soweto giants between March and September 2012, following Julio Leal's sacking.
2012/13 - Stuart Baxter (Chiefs) - This was the year Amakhosi did the double as they won both the league and Nedbank Cup. Baxter clinched their first league title in eight years.
2014/15 - Stuart Baxter (Chiefs) - Baxter, now dominant in the PSL, led Amakhosi to both the league and MTN8 trophies. He is the last foreign coach to have won the title.