PITTSBURGH -- One week after being knocked out of the most meaningful part of the season by lower-back tightness, Pirates second baseman Neil Walker has finally been cleared to conservatively resume baseball activities.

The hope is that Walker could return to the lineup by this weekend.

Walker was due to play some catch Monday morning and swing the bat in the indoor cage, and also pick up his running along with other agility drills. If he comes through these steps without setbacks, he would begin taking ground balls on Tuesday.

"He's got a chance to be back on the field by this weekend," manager Clint Hurdle said.

In Walker's absence, the Pirates have alternated Josh Harrison and rookie Brock Holt at second base. Holt got his second straight start in Monday afternoon's opener against the Astros, after going 2-for-4 with an RBI on Sunday in Milwaukee.

Harrison, who shifted to shortstop on Sunday, was out of the lineup Monday as veteran Clint Barmes returned to his post. In seven consecutive starts, Harrison went 8-for-27 (.296) and also contributed a memorable play when he crashed into St. Louis catcher Yadier Molina attempting to score a run early in the Pirates' 9-0 victory last Tuesday.

Hurdle fascinated by concept of 'spoiler'

PITTSBURGH -- The Brewers, who just treated the Pirates to a very harsh weekend in Milwaukee, are not your classic "spoilers." They are still the defending National League Central champions, and after two hot weeks are harboring dreams of a Cardinals-like charge into this postseason.

However, the Bucs will spend much of the season's last month in the company of bona fide also-rans, whose September pledge is to spoil contenders' hopes. Two of those clubs -- the Astros and the Cubs -- represent the opposition for a week-long homestand that began on Monday.

And the zeal with which these teams attack their spoiler tasks intrigues Pittsburgh manager Clint Hurdle.

"It's just interesting to me," Hurdle said. "Why now? Why do they now feel they can beat somebody they shouldn't beat? What happened to April and May and June and July? Do they have some vitamins, or what do we hand out?

"It's just crazy to me. But 'spoiler' is not just a media term. Do these teams now play looser? Yeah, that probably has something to do with it."

What will be of utmost interest to any Pirates fan younger than, say, 25, is that the Bucs themselves are no longer the spoilers, but the potential "spoilees."

Worth noting

• Through Sunday's loss to the Brewers, the Bucs had been double-digit strikeout victims in nine of their last 14 games. The club has whiffed 10-plus times in a total of 47 games.

• The Bucs began Monday's game needing only one more PNC Park victory to clinch only their second winning home record in the park's 12-year history. The Pirates were 43-38 at home in 2006.

Last word

"Anybody want to know anything about the players we have here today, who will actually be playing?"
-- Hurdle, after spending the first five minutes of his daily media briefing fielding questions about sidelined players such as Walker, Starling Marte and Chad Qualls.