McCluster suffered a sprained MCL in his right knee Nov. 19 in the first meeting between the Titans and Jaguars, and he has not practiced or played since.
Martin, who has been a healthy scratch for the Titans (2-9) the past five weeks, showed up on the injury report Thursday after aggravating an old injury.
''We're just being precautionary with him right now,'' interim coach Mike Mularkey said.
Linebacker Derrick Morgan was not in the open part of Friday's practice and is questionable with a shoulder injury. Morgan missed last week's 24-21 loss to Oakland with the injury and was limited to pass rushing against the Jaguars. He has been working through the injury for several weeks.
''I've been playing with it since Atlanta (on Oct. 25), so it's kind of been an on-going thing,'' Morgan said.
Other Titans on the injury report all practiced Friday. Safety Marqueston Huff (hamstring) is questionable for Sunday's game, while tight end Anthony Fasano (shoulder), nose tackle Sammie Hill (knee) and nose tackle Al Woods (ankle) are all probable.
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