[CTcard]

Does Irwin wear jersey #2 when playing WR and #30 when returning kicks ?  If so, why two different jersey numbers for the same player ?

Stanford (and most teams) have a player on offense and a player on defense with the same number.
That's perfectly fine, but causes a problem on special teams, as two players with the same number cannot be on the field at the same time. Brandon Simmons (also #2) plays on most special teams, so when Irwin goes in he needs a different number.

Happens quite often - you see guys with temp jerseys on special teams all the time.

[CTcard]

Does Irwin wear jersey #2 when playing WR and #30 when returning kicks ?  If so, why two different jersey numbers for the same player ?

Stanford (and most teams) have a player on offense and a player on defense with the same number.
That's perfectly fine, but causes a problem on special teams, as two players with the same number cannot be on the field at the same time. Brandon Simmons (also #2) plays on most special teams, so when Irwin goes in he needs a different number.

Happens quite often - you see guys with temp jerseys on special teams all the time.