Hamstring strain could sideline Cubs' Contreras 4-6 weeks

PHOENIX (AP) The Chicago Cubs say catcher Willson Contreras is expected to be out four to six weeks because of a strained right hamstring.

The NL Central leaders put Contreras on the 10-day disabled list before Friday night's game at Arizona. He was injured running to first base on Wednesday in San Francisco.

Contreras has been a major factor for the Cubs since the All-Star break, batting .311 with 10 home runs and 29 RBIs. Overall this season, he is hitting .274 with 20 doubles, 21 home runs and 70 RBIs in 102 games.

If he's out for six weeks, he would return with a little over a week left in the regular season.

Alex Avila, acquired at the trade deadline from Detroit, started behind the plate for Cubs on Friday night.was at catcher for Chicago on Friday night.

''Hamstrings are so unpredictable,'' manager Joe Maddon said. ''Let's just play it out.''

Catcher Victor Caratini was recalled from Triple-A Iowa. He hit .192 in an 11-game stint with the Cubs earlier this season.