There are many reasons why rookies in the NFL may struggle in adapting to the pro version of the game. One of which is a lack of familiarity of the people with whom they're doing battle on the field.

Steelers first round pick, OG David DeCastro and fourth round pick, NT Alameda Ta'amu, may not have to worry about that as much. They have a history of competing against each other dating back to high school.

DeCastro and Ta'amu both attended high school in the Seattle area (DeCastro at Bellevue High School and Ta'amu from Rainier Beach), and were roommates together at a high school all-star football game in California back in 2007.

When the two made their college choices, DeCastro elected to attend Stanford due to its sterling academic reputation. Ta'amu stayed in-state, and played four years for the hometown Huskies.

The two squared off In 2009-11, with Stanford thrashing the Huskies all three times. The Cardinal rushed for 446 yards in their final meeting, a 65-21 thrashing of the visiting Huskies.

Per a Seattle Times article leading up to the game, the two appear to be respectful of each other, and still maintain a level of friendliness.

Of Ta'amu:

Whatever happens, Ta'amu says he'll warmly shake DeCastro's hand afterward. "That's my boy right there," he said this week.

And DeCastro:

"He's a great guy," DeCastro said of Ta'amu.

The familiarity they share with each other will serve them well as they compete against each other, hopefully for the Steelers, for a very long time.