Soler's strikeouts not a concern for Maddon

CHICAGO -- Jorge Soler does lead all National League rookies in hits and was batting .313 in May entering Thursday, but he's also striking out more. Cubs manager Joe Maddon isn't worried.

"He's very young," Maddon said of the 23-year-old outfielder. "Sometimes you equate big people as being more mature as opposed to their age and birth certificate. This is a big, young man who is struggling at the Major League level right now. ... He's going to be fine.

"This guy's talent is prodigious and he'll come out on the other side," Maddon said. "In the meantime, you have to support him, you have to talk to him, you have to coach him, you have to help him and eventually he comes back to the other side. This is a player who every organization would like to have their hands on right now, and we happen to have him."

With two strikeouts on Wednesday and one more in his first at-bat on Thursday, Soler is leading the NL with 50.

• Catcher David Ross had to leave Thursday's 6-5 win over the Mets after an at-bat in the eighth because of abdominal tightness. He was to be re-evaluated on Friday. The Cubs are carrying three catchers. Ross has been matched up with Jon Lester, whose next start is Saturday against the Pirates.

• Infielder Tommy La Stella, on the disabled list since April 9 with right rib cage inflammation, was to begin a rehab assignment with Double-A Tennessee on Friday. La Stella played in two games before he was placed on the DL.

• Outfielder Billy McKinney, ranked No. 8 on MLB.com's list of Top 30 Cubs prospects, was promoted from Class A Advanced Myrtle Beach to Double-A Tennessee on Thursday. McKinney, 20, was batting .340 with four home runs, five doubles, two triples and 25 RBIs in 29 games with the Pelicans.

The Cubs acquired McKinney from the Athletics last July along with Addison Russell for Jeff Samardzija and Jason Hammel.