The former Liverpool captain expected some of the club's Under-21 starlets to feature in the starting line-up now that their relegation has been confirmed.
Thompson was speaking on Soccer Saturday after watching Championship-bound Villa slip to their 10th straight defeat with a 4-2 loss at home to the Saints.
The visitors were ahead on 15 minutes through Shane Long’s close-range header, before the Irish striker set up Dusan Tadic to make it 2-0 six minutes before the break.
Ashley Westwood manage to reduce the deficit in first-half injury-time with a low finish from the centre of the box, but the visitors restored their two-goal advantage with 20 minutes left when Tadic fired a deflected shot into the bottom corner from just outside the area.
Westwood again handed Villa a lifeline five minutes from time with his second goal of the game, but Sadio Mane killed off their hopes of a comeback with a stoppage-time header.
Fans had been hoping to see some of the club’s Under-21 starlets get a run-out on the afternoon after last weekend’s 1-0 defeat at Manchester United confirmed their relegation, but Black instead drew their ire after opting to stick with the likes of Leandro Bacuna and Joleon Lescott.
Irish centre-back Kevin Toner did make his senior debut for the club as a half-time replacement for the injured Micah Richards, but Thompson was expecting to see a lot more rookies involved given that the game was nothing but a dead rubber for the hosts.
“Interestingly, Kevin Toner made his debut at half-time, coming on for Micah Richards,” the former Liverpool captain told Sky Sports. “I don’t know why they don’t give these lads a chance anyway and have a look at them.
“He did ok, but it was a canter for Southampton. Shane Long was in acres of space to score the first, it was incredible, and I think the second goal caps everything for this Villa side.
“Bacuna makes a pass back into his own half and Long then gets past Joleon Lescott. It was shocking! These are the things which Villa have had to put up with up. The ball was a like a bar of soap at times for Brad Guzan.
"It was a very good afternoon for Southampton and they were in second gear."
Thompson was also left decidedly confused by Black’s decision to replace Jordan Ayew with Rudy Gestede just before the hour when the Ghanaian striker had been one of Villa’s few bright spots up until that point and did not seem to be injured.
"Villa showed a little bit of spirit and had a couple of half-chances late on,” Thompson added. “Gestede came on for Ayew, surprisingly, and the crowd were absolutely furious because Ayew has probably been one of the best ones. I thought he must have got an injury or something like that.”
Black later defended the substitution when speaking to the club’s official website after the match, explaining: “The fans will definitely have ideas on the players and the team they want to see. I have no doubt about that
“I think that multiplies because of the circumstances, but I can't be led down that road. I can't succumb to that.”