Level 6 Referee
Without wanting to rain on your parade, it can't be first teams. Even for friendlies there are strict rules around the level of officials needed, and if a Premier League's first team was playing you would realistically need at least an SG2 referee in the middle and at least one FL assistant, and no assistant would be below L3.
In really response to this, I was earlier in the season sent a message as a L7 asking me to Referee a Pre-Season game where the away team were an a Championship sides U23 team with 1 or 2 Lads that are actively playing for the first team.
The home team were a local United Counties team.