2015 NFL countdown: 57 days and Cardinals uniform No. 57

Today's number of the day is 57. There are 57 days until the Arizona Cardinals play their 2015 regular season opener at home against the New Orleans Saints.

57 is the jersey number we will look at today, as well.

The current No. 57 is an important player -- outside linebacker Alex Okafor, who broke out last season, in a sense, with eight sacks. Drafted in the fourth round in 2013, he played only a handful of snaps his rookie season before an injury ended his season. He started the 2014 season banged up, but managed to lead the team in sacks.

We hope for more in 2015.

Who are some other notable 57s?

A former fan favorite -- linebacker Ronald McKinnon wore 57 from 1996-2004. He was an undrafted success story. He made the team out of camp his rookie year. He became a starter in 1997 and started 128 games over eight seasons after that. He was a tackling machine, averaging over 115 total tackles in those eight seasons he started. His best season was 2000, when he racked up 157 total tackles, four sacks, two forced fumbles and a fumble recovery.

Niko Noga played five seasons -- four as a starter at linebacker -- for the St. Louis and Phoenix Cardinals from 1984-1988.

One other 57 -- linebacker Mark Arneson -- played and started nine seasons for the Cardinals. He played outside and middle linebacker as a starter for the St. Louis Cardinals from 1972-1980.

Who was or will be the best No. 57? Vote on it.

Do you have any other memories with players wearing No. 57? For more than the four players mentioned here, look at this list.