ST. LOUIS (AP) -St. Louis Cardinals manager Tony La Russa defended Chris Duncan all week from critics of his uncertain fielding and sporadic hitting. Then, a day after Duncan got the go-ahead hit and made a couple of nice defensive plays, he was sent to the minors.

Duncan was optioned to Triple-A Memphis to iron out his difficulties. The Cardinals recalled power-hitting outfielder Joe Mather from Memphis.

Mather was in the lineup Friday, batting second against the Pittsburgh Pirates.

Duncan had a two-run single in the first inning off Roy Oswalt on Thursday in a 3-2 victory over the Astros, but is batting .213 in May and .252 overall with four homers and 16 RBIs. He has struggled to regain his stroke since sustaining a sports hernia last season.

La Russa went out of his way to compliment Duncan's play after Thursday's game.

``This guy plays defense, on his worst day, average,'' La Russa said. ``If everybody on our roster was as talented, as tough a competitor and as great a teammate as that young man, we may never lose.''

But Duncan lost playing time in a competitive outfield situation behind Ryan Ludwick, Rick Ankiel and Skip Schumaker - all in their first year of pretty much regular duty. Ludwick had a .327 average, 13 homers and 39 RBIs, Ankiel had eight homers, 25 RBIs and seven go-ahead hits, and Skip Schumaker is the primary leadoff man, and had a .285 average with two homers and 15 RBIs.

La Russa considers all three of those players good enough defensively to play center field. The 6-5 Duncan, on the other hand, is awkward and often uncertain in the field, and accepted blame for taking a step back on a fall that landed in front of him in the Dodgers' 10-inning victory on Sunday.

``He blames himself for everything,'' La Russa said after Thursday's game.

The 25-year-old Mather is batting .315 with 12 homers and 24 RBIs in 38 games for Memphis, and has a six-game-hitting streak. He has 10 homers in May.

Mather was a third-round draft pick in 2001 out of Mount Point, Ariz., High School. He combined to hit 31 homers last season between Double-A Springfield and Memphis.

Duncan hit 21 home runs last year and 22 in 2006.Copyright © 2005 The Associated Press. All rights reserved. The information contained in the AP News report may not be published, broadcast, rewritten or redistributed without the prior written authority of The Associated Press.