The four-time All-Star had been penciled in to start Opening Day against the Los Angeles Dodgers back in March before taking a line drive off his left (pitching) hand in his final spring training start.

The blow broke a bone below his left pinkie, which landed him on the disabled list, from which the Giants plan to reinstate him Tuesday.

Bumgarner says he's ready to go, and probably didn't need one last injury-rehab start in the minors last week.

"As long as the front office says I'm ready, I guess I'm ready," Bumgarner said about being patient with the club's rehab approach. "I feel ready."

The Giants have gone 30-30 in Bumgarner's absence, which has been good enough to keep San Francisco within 1 1/2 games of the top of the National League West, a spot currently occupied by the Diamondbacks (31-28).

Even in the ace's absence, San Francisco's pitching has spearheaded a five-game winning streak. No starter has given up more than two runs in any of the club's last four games, during which the Giants have outscored the opposition 22-4.

Bumgarner steps right into the ring of fire Tuesday, facing an Arizona team that already has won two series -- both 2-1 -- over the Giants this season.

He's gone 9-10 with a 2.58 ERA in 30 career meetings, including 29 starts, against the Diamondbacks.

The injury was Bumgarner's second in 13 months. He suffered a separated shoulder last April in a dirt-bike accident in Colorado.

On that occasion, he sat out almost three months, returning July 15 to find the Giants 27 games out of first place in the NL West, having gone 29-46 in his absence.

Bumgarner's return last season came at San Diego, where he allowed three runs and four hits in seven innings in a 5-3 loss.

Despite the 87-day layoff, he threw 104 pitches.

He went on to go 4-6 in 13 starts the rest of the season.

Bumgarner will run head-to-head the Diamondbacks' best pitcher this season, left-hander Patrick Corbin (5-2, 2.99).

Corbin pitched a one-hit shutout in a 1-0 home win over the Giants in April. It raised his career record against them to 6-7 with a 3.16 ERA in 21 head-to-heads, 19 of which have been starts.

He's rarely pitched well in San Francisco, however, struggling to a 1-4 record and 4.66 ERA in eight starts.

Corbin will see a Giants lineup that's coming off one of its most powerful displays of the season in Monday's 10-3 win in the series opener. Four Giants hit homers in the game, matching their season-high, as San Francisco won its sixth straight at home.

The Giants had scored a total of just 13 runs in their first six meetings against the Diamondbacks in April.

Arizona has lost nine of its last 10 on the road.