49ers' Arik Armstead signs rookie deal

The San Francisco 49ers now have all of their draft picks under contract.

San Francisco signed first-round pick Arik Armstead to a four-year deal on Friday.

Armstead became the first of the 49ers' 10 draft picks when they took him 17th overall after trading down. The pass rusher will add some size to a revamped defense under head coach Jim Tomsula.

It remains to be seen if Armstead will start right away. Tomsula has already said he won't rush Armstead on the field and will allow him time to develop his craft at the pro level.