SAN DIEGO -- Padres rookie first baseman Yonder Alonso is having a strong debut campaign at the plate, settling into the heart of the San Diego order and leading all Major League rookies with 29 doubles. But his defense starred alongside his bat in Friday's 3-1 win over the Mets, as the 25-year-old dug out several tough throws in crucial situations.

One of those situations came in the ninth inning, when another pretty good corner infielder, third baseman Chase Headley, barehanded a slow roller off the bat of Jason Bay and fired low to Alonso. Alonso picked it on a short hop to change the complexion of the inning entirely, something manager Bud Black definitely noticed.

"Chase had to make a very good play on Bay's ball in the ninth, but Yonder, if he doesn't pick it, here comes the tying run to the plate," Black said.

That play, and others like it in recent weeks, show just how much the youngster has grown in his first 100 games: The success he's had recently is a far cry from a shaky first couple months in which he accumulated the lion's share of his eight errors.

"You wipe out the first six weeks, he's played really solid defense," Black said. "I think in April and early May there are some things he would definitely want to do over. ... He's been much more fundamentally sound around the bag. ... He is much improved."

Alonso has worked with third-base coach Glenn Hoffman on picking those short hops, and has also shown significant improvement in his awareness around the bag, as evidenced by his quick retreat to first prior to a Chris Denorfia throw from right field Friday night. Improvements like those, Blacks says, are just as important as Alonso's continuing development as a big league hitter.

"Defense at first base is, for me, underrated. It is a crucial position defensively," Black said. "If you have a defensive first baseman, it is a huge advantage. And if he can hit and play defense? Boy, is that a bonanza."

Denorfia always looking for '9-3 groundouts'

SAN DIEGO -- While Carlos Quentin's run-scoring collision may be the standout moment from Friday night's 3-1 Padres win, right fielder Chris Denorfia nearly completed a similarly memorable play in the third inning.

With Mets' starter R.A. Dickey at the plate, Denorfia was playing a shallow right field and shading the foul line in anticipation of the kind of opposite-field blooper that is often a product of a pitcher's defensive swing. What he got instead was a solidly struck line drive. Denorfia charged and fired a wild one-hopper to first, where Yonder Alonso picked it for what looked to many in the ballpark to be a 9-3 groundout.

Dickey was ruled safe in the bang-bang play, but the Padres had almost completed a rare feat: throwing a runner out at first from the outfield. Denorfia has made a few such attempts this season, opportunities he says are the product of perfect circumstances.

"There are certain situations where I can play in and over towards first base, and if a guy hits a line drive to me, I usually have a shot," Denorfia said.

Those chances are few and far between, and in order for Denorfia to take them, he says, his first baseman must also be aware and ready for a throw he's not used to receiving.

"[Alonso] is really good at getting to the bag, he can smell it too when it's coming," Denorfia said. "If you put a good charge on it, and he's there, you just try not to throw it away."

Alonso was quick to point out that a throw from right is a strange play for the first-base umpire, too.

"That play might happen once every two, three years. It never happens," Alonso said. "So it's a hard play all around -- for the right fielder, to me, and for the umpire."

Short hops

• When Kip Wells was designated for assignment Friday, Black announced that left-handed pitcher Eric Stults would move back into the starting rotation. What wasn't clear was when Stults would get the ball, and whether he would assume Wells' spot as San Diego's fourth starter.

Black clarified prior to Saturday's game, announcing that Stults would, indeed, take over that fourth spot, and therefore start Monday's series opener with the Cubs. Ross Ohlendorf will pitch Tuesday, and ace Clayton Richard will get the ball on Wednesday.

• Black said Saturday that injured pitcher Anthony Bass is scheduled to throw sometime in the middle of next week. Bass has been on the disabled list retroactive to June 21 with right shoulder inflammation. The 24-year-old was 2-7 with a 4.70 ERA in 16 games this season, 14 starts.

• With his clutch, eighth-inning strikeout of Mets star David Wright Friday night, Padres reliever Luke Gregerson extended his streak of scoreless innings to 12 1/3. Closer Huston Street followed with a four-out save, extending his scoreless streak to 17 1/3 innings. He last allowed a run on June 17 against Oakland.