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4/22/2014 7:19 P.M. ET

Liriano's April woes keep up amid frigid weather

PITTSBURGH -- Francisco Liriano's open secret, hidden a year ago behind a broken right arm, is out: The guy and the month of April just don't get along.

Pirates fans couldn't be clued in to that in 2013, because Liriano did not make his first start until May 11, and immediately took off.

Good to go this time out of the gate, Liriano has so far contributed five winless starts to his lifetime April resume: a 5-17 record with a 5.84 ERA.

"Yeah, Aprils have been difficult for me," Liriano conceded, with a weak smile. "It's just the cold. My speed usually isn't there until it gets warmer and I feel looser. And I don't have a good feel for the ball on breaking balls."

Speaking of the early season cold weather -- generically, not in specific reference to Liriano, a native of the Dominican Republic -- Clint Hurdle noted a while back that "Latin pitchers hate that."

Colder temperatures obviously return at the end of the season. Sure enough, Liriano's career September record is 7-12, with an ERA of 5.48.

In the four months in-between, he is 57-36, and his highest ERA in any month is 4.04.

So the good news could be that Liriano has only one more April start remaining, then he can roar into May like a lion.

With Wandy out, Thursday's starter still unknown

PITTSBURGH -- The Pirates' spot starter in Wandy Rodriguez's spot on Thursday may not be as obvious as originally believed.

In the wake of Rodriguez going on the DL with a sore right knee on Monday, manager Clint Hurdle had implied that the choice would be either of the two long men in the bullpen, Jeanmar Gomez or Stolmy Pimentel.

"We've got a couple of different guys in-house. We'll see who lines up," Hurdle had said.

The manager corrected himself on Tuesday, explaining, "When I said 'in-house,' I didn't just mean somebody on the club now. I meant within the organization."

Apparently, the club is also considering calling up someone out of the rotation of Triple-A Indianapolis.

The leading prospect there would seem to be right-hander Brandon Cumpton, who is scheduled to start for the Indians on Wednesday. If he is pulled from that assignment, the Pirates' plans will become transparent.

Major League veteran Jeff Locke is out. He pitched for Indianapolis on Monday night.

Rodriguez's fill-in is not the only mystery surrounding the veteran lefty. The possible length of his absence is also an unknown.

While deferring to GM Neal Huntington, chiefly responsible for following up on injuries, Hurdle allowed that "knees can be different for different people."

Rodriguez had fluid drained from the knee on Monday, when he also underwent an MRI, results not yet shared.

"You can get a knee drained and have to get it drained again in two months," Hurdle said. "I know people who have had their knee drained a couple of times and had surgery in the winter. It depends on the guy. We'll just have to wait and see."

Prospect Polanco keeps up strong start at plate

Outfielder Gregory Polanco, the Pirates' No. 1 prospect and No. 13 overall, continued his torrid start to the season Tuesday. He entered the day leading the International League with a .406 batting average and improved on that mark by going 3-for-5 as Triple-A Indianapolis defeated Toledo, 11-6.

Polanco also hit his third home run of the season, scored three runs and stole a base in the victory.

In 18 games this season, Polanco has at least two hits in 10 of them. After his big game Tuesday, he is hitting .419/.456/.649.

As he has in every game this season, Polanco played right field Tuesday night. He was primarily a center fielder in past years, but as he approaches the Major Leagues, the Pirates are preparing him to play in the same outfield as 2013 National League MVP and current Bucs center fielder Andrew McCutchen.

First number, last word

52: Andrew McCutchen's home runs at PNC Park, the latest in the eighth-inning Monday night, breaking a tie with Garrett Jones for second place all-time; Jason Bay leads with 61.

"If we win and I go 0-for-4, it's still a good day." -- Ike Davis, whose grand slam in a 6-5 win over Cincinnati made Monday a really good day.

Worth noting

• When Neil Walker followed up his Opening Day 10th-inning homer with his tie-breaking single in the ninth inning Monday night, he became the first Pirates player in the last 40 seasons to have two walk-off hits in one April.

• The Bucs began Tuesday night's game six games behind National League Central leader Milwaukee. In 2013, they never trailed in the standings by more than four games.

Jason Grilli, aka "Grill Cheese," will observe National Grilled Cheese Month on Wednesday by serving -- what else? -- grilled cheese sandwiches at the Greater Pittsburgh Community Food Bank to Pittsburgh area food bank clients. Land O'Lakes, Inc. is donating 40,000 pounds American Cheese product for the initiative that will provide over 33,000 meals to families in need.

Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. Teddy Cahill is a reporter for MLB.com. Follow him on Twitter at @tedcahill. This story was not subject to the approval of Major League Baseball or its clubs.