Baba Rahman, who was given the number 17 shirt upon his arrival will now hand it off to Pedro. The Spaniard wore the number for Barcelona for many years until switching to the number seven shirt for the 2013-14 campaign. As you may remember, Eden Hazard wore 17 in his first two seasons at the club before being given the number 10. The number has been worn by Jose Bosingwa and most recently Mohamed Salah.
After conceding his newly acquired number, Baba chose the number six shirt. Apparently, this was his preferred choice all along. It's unclear why he didn't get a chance to have it before the switch. Nathan Ake wore the number six shirt last year but has since gone on loan to Watford.
To sum it up:
Pedro = 17
Baba Rahman = 6
Now go buy some shirts!