The St. Louis Cardinals held a closed practice today in an attempt to return their attention to football following the death of tight end J.V. Cain Sunday night.

Tests to determine the cause of death have been inconclusive, team officials said. An autopsy ruled out heart attack, but microscopic studies are under way to search for a condition that may have gone undetected.

Physicians who conducted the autopsy said the specific cause of Mr. Cain's death may never be known.

"I've got a thick file of cases like this, where we never find out what it was," said St. Charles County Coroner Joseph Mueller. "It's very possible we won't in this case." Results of further tests are not expected for several days.

Tentative funeral plans call for a memorial service in St. Louis before burial in Houston, his hometown, on Friday. Mr. Cain's wife Jean will receive $50,000 in insurance, plus a pension of $1,000 a month for four years and $333 a month thereafter, NFL officials said.

The San Francisco 49ers acquired on waivers New York Giant quarter-back Jerry Golsteyn and Dallas Cowboy rookie offensive lineman Bob Hukill. Golsteyn was cut by the Giants Monday.

Hukill, the Cowboys' first fifth-round draft pick, played both center and tackle at North Carolina. The 49ers hope to use him at offensive tackle.