This weekend on The iHeartRadio Countdown with Mario Lopez Mario is out due to surgery to repair his torn bicep! Don't worry though the incredibly talented and hilarious Lewis Capaldi will be filling in as host. His song 'Someone You Love' was #2 on the charts last weekend and there are rumors swirling that it may be topping the charts soon! So Lewis will break down his music, talk about his album, play some of his favorite songs and countdown the rest of the top 20 songs in the land! Tune in!