HOUSTON | Veteran reliever Kyle Farnsworth appears headed to the disabled list after a magnetic resonance imaging exam revealed a grade-two strain and partial tear of his right groin.</p><p>Farnsworth confirmed the diagnosis Thursday afternoon before the Royals departed for their weekend series in Pittsburgh.</p><p>&ldquo;I just found out about it,&rdquo; he said. &ldquo;I don&rsquo;t know what the plan is yet.&rdquo;</p><p>Club officials want to digest Farnsworth&rsquo;s injury, and its impact on their bullpen, before determining a starting pitcher for Saturday&rsquo;s game against the Pirates.</p><p>Farnsworth needed to be helped from the field Wednesday night after collapsing at the mound following a pitch to Houston&rsquo;s Pudge Rodriguez. Farnsworth is now able to walk unaided, but he seems certain to end up on the disabled list.</p><p>The Royals trimmed their staff to four starters last Saturday by optioning Kyle Davies to Class AAA Omaha before activating reliever Robinson Tejeda from the disabled list. An open date Monday alleviated the need to replace Davies in the rotation until Saturday against the Pirates.</p><p>The two leading candidates appear to be veteran lefty Bruce Chen and rehabbing right-hander Sidney Ponson, who was 1-5 with a 7.27 ERA earlier this year in 11 games, including six starts.</p><p>A strained right elbow forced Ponson to the disabled list after a May 29 relief appearance against the White Sox. He has made two rehab starts at Omaha and is tentatively scheduled to start again tonight at Memphis.</p><p>The Royals perhaps tipped their hand Wednesday by limiting Chen to two innings and 23 pitches in Omaha&rsquo;s 7-5 loss at Memphis.</p><p><strong><span class="subhead">Futures selection</span></strong></p><p>Left-hander Danny Duffy will be the Royals&rsquo; lone representative among the 50 minor-league players selected Thursday to participate in the All-Star Futures Game on July 12 at Busch Stadium in St. Louis.</p><p>Duffy, 20, is 6-2 with a 2.85 ERA in 13 starts at Class A Wilmington with 66 strikeouts and 20 walks in 72 2/3 innings. He pitched one scoreless inning Tuesday for the Carolina League All-Stars in their 2-1 loss to the California League All-Stars in Lake Elsinore, Calif.</p><p>The Royals selected Duffy in the third round of the 2007 draft. He was the Midwest League pitcher of the year last season after going 8-4 with a 2.20 ERA in 20 starts for Class A Burlington.</p><p><strong><span class="subhead">On to Pittsburgh</span></strong></p><p>The Royals played four series in Pittsburgh over the first five years of interleague play, but today marks their first visit to PNC Park since 2001. The teams did meet in 2006 at Kauffman Stadium, when the Royals swept three games for a 12-8 lead in the all-time series.</p><p>This weekend&rsquo;s series concludes the Royals&rsquo; interleague schedule.</p><p>The pitching matchups are somewhat scrambled. </p><p>The Royals continue to hedge on a starter for Saturday, while Pittsburgh created a hole in its rotation Thursday by optioning right-hander Ian Snell to the minors. Snell had been scheduled to start Sunday&rsquo;s series finale.