49ers Place DT CJ West on Injured Reserve, Sign Naquan Jones

The short version
- 49ers placed DT CJ West on injured reserve; injury undisclosed
- San Francisco signed DT Naquan Jones off the Vikings' practice squad
- WR Brandin Cooks signed; CB Jakob Robinson released; DL Viliami Fekhoko Jr. added
- James Thompson Jr. is out with a high-ankle sprain
- Only three healthy defensive tackles remain on the roster
San Francisco added defensive line and receiver help while losing another interior defensive tackle to injured reserve ahead of Week 4.
The San Francisco 49ers placed defensive tackle CJ West on injured reserve on Wednesday. The nature of his injury has not been disclosed, though head coach Kyle Shanahan was expected to address it later in the day.
To shore up the roster, the 49ers signed defensive tackle Naquan Jones off the Minnesota Vikings' practice squad. The team also signed wide receiver Brandin Cooks.
San Francisco also released cornerback Jakob Robinson from the practice squad after signing defensive lineman Viliami Fekhoko Jr.
West's absence deepens a problem at defensive tackle. James Thompson Jr. is already sidelined with a high-ankle sprain, leaving defensive coordinator Raheem Morris with players who joined the roster only within the past week.
The 49ers currently have three healthy defensive tackles and are likely to elevate another from the practice squad.