They've also continued the Toronto Blue Jays' recent troubles.Walker and the Pirates will be looking to make things a bit easier on themselves Sunday as they attempt to sweep this three-game series from the sputtering Blue Jays.Walker is 7 for 10 with three doubles, three RBIs and four runs over the past three games, and it's his production over the past two that has Pittsburgh (12-18) hoping it's beginning to turn things around.The second baseman doubled on two of his three hits Friday, but his leadoff single in the ninth started a three-run rally in a 6-5 win over Toronto (13-17). He followed that by singling and scoring in the Pirates' four-run seventh inning Saturday before delivering a tiebreaking, two-run double in the eighth to complete the rally for an 8-6 win.Those dramatics are part of Pittsburgh's .387 average in this series, which is welcome after the team entered this series having dropped 10 of 12 while batting .217 and averaging 2.8 runs."You've got to believe, though. Can you have faith?" said shortstop Jordy Mercer, whose pinch-hit double in the seventh inning tied the score Saturday.The Pirates will turn to Edinson Volquez (1-2, 3.21 ERA), who for the first time this season isn't starting opposite one of the best pitchers in baseball.Through five starts, Volquez has taken the mound twice opposite St. Louis' Adam Wainwright and Milwaukee's Yovani Gallardo, and once against Johnny Cueto of Cincinnati.The right-hander fell against Wainwright last Sunday, when he gave up six runs and two homers before being pulled with two outs in the sixth inning of a 7-0 defeat to the Cardinals.He had a 2.08 ERA over his first four starts, but has been given an average of 2.27 runs of support this season against some of the NL's best pitchers."I don't even think about that," Volquez told the team's official website. "I just want to do my job, every five days. I don't care who I face."Volquez should be more concerned about his own performances against the Blue Jays. He's 0-2 with an 8.16 ERA over three starts, allowing four runs in five innings with the Padres on June 2.Toronto has lost eight of 10 games, thanks in large part to the pitching staff's 6.65 ERA -- 8.81 from the bullpen."I don't think that we're going to start pointing fingers at anybody just because we've lost a couple games in a particular fashion," right fielder Jose Bautista said.Giving the ball to Dustin McGowan (1-1, 5.87) may not help. The Blue Jays have lost each of the right-hander's last three starts, a stretch in which he has no record and a 7.07 ERA.He showed some improvement Tuesday, yielding three runs -- two earned -- and three hits in six-plus innings of a 10-7 defeat at Kansas City."I'm really encouraged," McGowan said. "I went deep into the game. That's all I've been wanting to do. Sometimes the results are overshadowed by the innings you've pitched. But good things happen when you get deep in games."McGowan gave up three runs over five innings in an 8-5 win in his only career start versus Pittsburgh, on June 22, 2008.