Heidenheim coach Frank Schmidt will miss the final Bundesliga game of the season next weekend against relegation-threatened Cologne after he had to undergo an ankle surgery, the club said on Sunday. The operation, which will be followed by several days in hospital, “cannot be carried out on any other day after the end of the season,” Heidenheim said. Schmidt said that the reason for the operation was a broken ankle from his time as a player at Alemannia Aachen and the resultingarthrosis with increasing pain. “This operation had actually already been planned last year. However, due to our promo…