The likes of Amazon and Facebook will "absolutely" enter the bidding war when the next round of television rights come up for tender, according to Manchester United's executive vice-chairman Ed Woodward.

Premier League football has been shown on Sky Sports since the league's inception in 1992, with BT Sport -- which owns Champions League and Europa League as well as some Premier League rights -- entering the market three years ago.

The current Premier League deal, which runs through to 2019, is worth £5.14 billion -- an eye-watering amount even for what many consider to be the most popular league in the sport.

Viewing habits are changing, though. The English Football League has this season allowed clubs to stream its games overseas through the 'iFollow' platform, while from 2019 that service will be available on home soil for midweek games from 2019.

Amazon has started live-streaming NFL games this season and in some overseas countries it is commonplace for fans of sports to be able to purchase subscriptions to only watch their team, should they wish.