Auto-populate on one tab based on a list and value from another

Greetings all. I am trying to come up with a formula that would auto-populate on one tab based on a list and value assigned on another. I have attached a sample workbook. I have tried IF statements, INDEX and MATCH and have not been able to figure it out. As you can see from my workbook, I am trying to place the groups of 4 players each from the "Players" tab onto the appropriate group number under the "Groups" tab. I would be manually entering a number 1-16 in the white box next to each group of 4 players. I hope I have explained this well enough. Thanks in advance if anyone can help me with this!