The Reds defender was on the bench as the Three Lions got their campaign up and running with a 2-1 victory over Tunisia on Monday night.
The following evening, Mane captained Senegal to a 2-1 success against Poland in Group H with Alexander-Arnold watching closely on television at England’s training base.
"I try to watch every one of my club-mates' games out here, I watched their first game and I want to see him do well,” said Liverpool’s No.66.
"It's only right we all support each other in that sense. Whenever I watch Senegal I want to see them win and the same with my other teammates.