General manager John Mozeliak said Tuesday that the team did not expect Fuentes back this season, adding "I didn't close the door on anything but I don't anticipate it." He added he could tell "that something was bothering him."
Fuentes will not count against the 40-man roster while on the restricted list and won't be paid.
He called me yesterday and said he was dealing with some personal issues, and at time he said he just could no longer play for us," Mozeliak said. "I did not dig in on it. Clearly, he was not looking to share exactly what was going on with me."
Mozeliak said Fuentes' decision had nothing to do with his role on the team.
The Cardinals are on the verge of getting left-handed starter Jaime Garcia back.
Garcia, out since early June with a shoulder injury, threw 93 pitches in five innings in his fourth injury rehab start Tuesday night for Triple-A Memphis. He struck out eight and walked three and left trailing Salt Lake 2-0.
Garcia won 13 games each of his first two seasons in 2009 and 2010, but is 3-4 with a 4.48 ERA in 11 starts this year.
Garcia could take over Sunday's turn in the rotation from rookie Joe Kelly, who started Tuesday night against Arizona. Kelly, 2-5 with a 3.47 ERA, would move to the bullpen.
"Possibly, yes," Mozeliak said. "Two things, we'll see how he throws and how he feels tomorrow. That'll be really what dictates our next move."
The 37-year-old Fuentes signed as a minor league free agent last month and has appeared in six games, totaling five innings. The four-time All-Star closer had been released by Oakland, which is paying the majority of his $5 million salary. St. Louis was responsible for only a prorated share of the $480,000 minimum.
St. Louis had been counting on Fuentes providing a veteran arm, considering him a trade deadline pickup.
"Really, I was disappointed frankly," Mozeliak said. "He played into how we made decisions, so to have it end this way is definitely disappointing. But there's no looking back for us at this point."
The 22-year-old Rosenthal was 0-1 with a 4.50 ERA in four games covering four innings with the Cardinals last month and made his major league debut on July 18. Since being optioned back to Memphis on Aug. 1, Rosenthal had 13 strikeouts in 10 innings.
Mozeliak said first baseman Lance Berkman, on the DL since Aug. 3, was not close to being ready to returning. Matt Adams, impressive as a fill-in at first base, had surgery Tuesday for a bone spur in his right elbow.