CHICAGO -- Cincinnati Reds shortstop Barry Larkin was placed on the 15-day disabled list Monday with a strained left calf.

Larkin, in his 18th season with Cincinnati, was injured while legging out a triple last Thursday in Houston. He has not played since, and was put on the DL retroactive to Friday.

It's another blow to the struggling Reds, who lost star center fielder Ken Griffey Jr. to a dislocated right shoulder April 5. They were 4-8 heading into Monday night's game against the Chicago Cubs.

When Griffey got hurt, there was talk of Cincinnati moving Larkin to center field to fill in. Instead, the 11-time All-Star and 1995 NL MVP is headed to the disabled list for the fourth time in the last four seasons.

To replace Larkin on the roster, Cincinnati activated infielder Juan Castro from the disabled list. He was rehabilitating an injured knee at Triple-A Louisville.

Reds manager Bob Boone thought it best to put Larkin on the DL partly because of the team's lack of depth in the infield.

''He didn't think it was worth it taking the risk, and that coupled with the fact that we are short with infielders,'' Larkin said. ''It's a (bad) situation to be in. Obviously, I can't help the team in the situation I'm in right now.''

Larkin is batting .222 in nine games, with three hits in his last 22 at-bats (.136). He will return to Cincinnati on Tuesday to start a rehabilitation program.