The Kansas City Royals placed right-hander Trevor Cahill on the 10-day disabled list with shoulder impingement syndrome on Thursday, the team announced. Cahill, acquired by the Royals in a multiplayer trade with the San Diego Padres, has struggled in three starts with Kansas City. He has a 8.18 ERA in three starts, allowing 10 earned runs in 11 innings. He also has walked nine batters while striking out just six and has allowed 18 hits, including four home runs. The Royals recalled right-handed reliever Kevin McCarthy to take Cahill's spot on the roster. McCarthy, 25, has pitched in 21 innings for the Royals this season, posting a 2.14 ERA with a 1-0 record. He was 1-1 with a 3.13 ERA in 31? innings at Triple-A Omaha this season.