“Next man up’’ is a hockey axiom based in resolve and bravado. It is not intended to be an operating philosophy. Two months into a season they hoped would be less volatile than the previous one, it has become exactly that for the Flyers. Injuries to Andrew MacDonald, Shayne Gostisbehere, and Radko Gudas – at one point, simultaneously – have forced Flyers coach Dave Hakstol to mix, match, and hope his way through a grueling early schedule against the heavier Western Conference, and the results at times were eye-covering. Even now, as the veteran MacDonald appears ready to rejoin the lineup as soon as Tuesday night, Hakstol will have to deal with the lengthy absence of his other experienced blueliner, Gudas, who was handed a 10-game suspension Sunday night after a phone hearing with the NHL’s Department of Player Safety. Gudas had received a match penalty in the first period Thursday in Winnipeg after slashing Mathieu Perreault on the back of his neck as he was on all fours. The suspension is the third of the 27-year-old Gudas’ career, all within the last three seasons. That history was a factor in the length of the new ban. But the suspensions tell only part of the story. For each time Gudas has been forced by the league to sit, there are a handful in which the penalty issued on the ice was deemed sufficient. A week before he was suspended for hitting Boston’s Austin Czarnik in the 2016 preseason, a boarding hit on the Rangers’ Jim Vesey – for which he was given a major and game misconduct – was reviewed by the NHL and no suspension added.