Manchester United have plenty of options at centre-back when everybody is fit – but having everybody available has been an issue. When Manchester United re-signed Jonny Evans last summer, nobody expected the Northern Irishman to play a prominent role. He has ended up playing 24 matches this season. Evans was not always used as a last resort. Earlier in the season there was lots of discussion when the 36-year-old was repeatedly picked ahead of World Cup winning defender Raphael Varane. Varane later regained his place in the team, and it seems there may have been more to his absence than initial…