PHOENIX – Brandon McCarthy has a visit to the nail salon in his future.

McCarthy allowed four runs — two earned — and five hits and three walks in four innings in the Oakland Athletics' 5-5, 10-inning tie against a Chicago Cubs split squad on Tuesday.

He spent the day battling a torn middle fingernail on his right hand, an injury he'll fix with a fake nail applied at a nail salon.

"I wish it had torn away a couple of days ago so I could have put a false nail on it," said McCarthy, who was making his final start of the spring. "It makes it hard to complete any pitches."

McCarthy, who will make his first career Opening Day start on March 28 against the Seattle Mariners in the Tokyo Dome, was in trouble from the first pitch, facing only four batters before giving up the game's first run.

Tony Campana doubled to left, aided by Coco Crisp's ill-advised, last-second lunge for the quickly dropping ball, and Ian Stewart drew a one-out walk. Joe Mather hit an RBI single to center and Steve Clevenger hit a sacrifice fly to left to give the Cubs a 2-0 lead.

"He game up some 0-2 hits which shows he probably wasn't as precise as he'd like to be," A's manager Bob Melvin said.

McCarthy allowed two unearned runs in the fourth on an RBI single by Alfredo Amezaga and a run-scoring groundout from Edgar Gonzalez.

The right-hander then went to the bullpen to throw another 20 pitches.

"I wasn't sharp by any means," McCarthy said. "Getting in the 90 pitches was the thing for the day. I just worked through it. It's a cliché, but I just needed to get my work in."

Cubs starter Rodrigo Lopez, a candidate to earn a spot in the bullpen, allowed one run and three hits in five innings. He struck out four and walked one.

Kila Ka'aihue, who is competing with Brandon Allen for the first base job, hit a towering home run off the scoreboard in right-center field in the eighth, then doubled home the tying run in the ninth.

"Kila's at-bats seem to be getting better and better," Melvin said. "It's definitely wide open."

Notes: Gonzalez had an RBI double taken away and the Cubs lost an apparent run in the sixth when he was called out at first on appeal for missing first base. ... Crisp was shifted to left field to make room for Yoenis Cespedes, who will open the season in center field for Oakland. "It'll take him a couple of days to settle in but he'll be fine," Melvin said. ... Jemile Weeks committed errors in consecutive innings, both on grounders by Clevenger. ... Before the game, the Athletics optioned RHP Brad Peacock to Triple-A Sacramento. Peacock had allowed 11 runs — 10 earned and 12 hits and four walks in just seven spring innings over three appearances. ... After the game, the A's optioned LHP Pedro Figueroa to Sacramento.