"I would ban him. He has become a Germany international and is of great value to the team. But we have to get these things out of sport. Children are watching, you don't do something like that," Hamann fumed on Sky on Saturday.
So what had happened? Just under an hour had been played in Mönchengladbach. The visitors from Mainz led 2-1 when the home side won a handball penalty. Amid the usual jostling before the kick, TV cameras caught Amiri scraping at the penalty spot with the studs of his boot.
Referee Robert Hartmann and his officials missed the Mainz midfield star's action. Whether it had any influence on the miss that followed is pure speculation. Gladbach defender Kevin Diks then smashed the ball against the right-hand post.
Hamann felt Amiri had behaved in a "grossly unsporting" manner and had "crossed a line by a long way". The former Bayern star called for "a one-match ban".
Gladbach did level shortly after Diks' miss. New signing Isac Lidberg made it 2-2, but Mainz restored control and moved 4-2 ahead through goals from Eric Martel and Danny da Costa shortly before full-time. Shuto Machino's converted handball penalty deep into stoppage time, with Amiri already substituted, came too late for Gladbach.
Getty ImagesWho will be the new coach at Borussia Mönchengladbach?
Borussia slipped to the bottom of the table after their fourth defeat in the fourth game of the season, overtaking Hamburger SV, who celebrated their first win of the season against 1. FC Cologne. In Gladbach, all signs now point to Alexander Blessin succeeding Eugen Polanski, who had been dismissed after the third matchday. On Saturday, interim coach Jan-Moritz Lichte took charge of the five-time German champions.
Whether Amiri will face consequences for his action remains unclear. The 29-year-old now has the two internationals against the Netherlands and Greece on the schedule. Amiri is part of the first of two DFB squads named by new Germany coach Jürgen Klopp for the upcoming total of four matches for the Germany national team.