Xabi Alonso is still trying to rotate his team players to see their specialties or who is good at which position. So that's why he is using Velverda's right-winger position. Like, mainly he is using 3-1-4-2 in which Alexander Arnold will work on the right overlap parallel to Velverda by making a run to help him with crosses towards the box. Now we don't know if Xabi Alonso will use these tactics for the rest of the season or if he is just estimating the player efficiency.
However, Xabi Alonso attitude towards Rodrigo is not too good, like he didn't want him to be part of his plan for next season. You need to understand that it not a rumor it a legit report....
Last games when defeating Dortmund, Xabi Alonsi used formation 4-3-1-2 and likely he not prefer for winger position as left or right side and its difficulty for Rodrygo get regular position. So far in last four games at FIFA Club World Cup, Alonso interested for playing Valverde at the right winger side and usually position filled by Rodrygo under Carlo Ancelotti era. Most appearances players likely Arda Guler he can plays not only as midfielder but many time he filled left or right winger side and in last several games performed quit well making two assists when Madrid eliminating Dortmund.
In my opinion, Rodrygo possibility get regular position under Xabi Alonso era almost over how his difficulty get more minutes playing at FIFA Club World Cup match, Alonso very interested for playing Arda Guler at the early minutes and moving Valverde as righ winger position than playing Rodrygo as main player.