Bartell has a broken left shoulder blade, a source told ESPN.com. Because no surgery is needed, his recovery time could be less than six weeks. There is hope he could be back in four weeks. He is meeting with a specialist to get more information.
The Raiders had high hopes for Bartell when they signed him to a one-year contract this offseason. He had success in his career with the St. Louis Rams, but he missed last season with a neck injury.
This injury further hurts one of Oakland's thinnest areas for the time being.
The Raiders announced Tuesday that Ford will undergo surgery on his injured left foot and miss significant time. Ford hurt his foot Aug. 17 in an exhibition game against Arizona. He missed six games with the same injury last season.
Information from The Associated Press was used in this report.