For starters, Kalvin needs to return to pre-season with 100% commitment to show Pep why he should merit far more involvement than the pitiful number of minutes he got last season.
I've still got no idea why he decided he needed a full holiday entitlement after the WC as he barely played for us before it and not at the tournament either Then to compound that by returning so out of condition that Pep needed to vent his fury publicly is staggering. This will be the greatest comeback since Lazarus if he can turn it around for us