SAN DIEGO — While they were sustaining a 5-4 loss yesterday, there were indications the Mariners also may have come close to leaving one of their lead players with the San Diego Padres.

Odds leaned heavily on that being second baseman Bret Boone; or less likely, pitcher Jamie Moyer.

Although the San Diego is known to have very little payroll leeway, the Padres need a starting pitcher and a second baseman more than anything. They will get Snohomish's Adam Eaton back from a finger injury next week to help ease their rotation need, but will be without second baseman Mark Loretta until mid-August.

In addition, the Padres are known to have a great appreciation for Boone, who grew up in this area and played for San Diego in 2000 before he signed to return to Seattle, where he has played since.

Close as it may have gotten, however, a source said the trade had gotten off track at some point before yesterday's game. San Diego's win gave them the series victory, despite Mariners rookie Rene Rivera's first major-league homer for three runs and a 4-4 tie in the seventh, and a remarkable effort by Boone.

The Mariners infielder and team leader put on a display that may prompt further discussions between Seattle general manager Bill Bavasi and his San Diego counterpart Kevin Towers. The two spent a considerable amount of time talking over the weekend, likely about Boone.

With his sixth homer for Seattle's first run in the fifth and an astonishing dive and grenade-toss flip from a prone position to start a double play in the bottom of that inning, Boone capped a showcase series that included four hits and two superb defensive plays in the first two games.

While Seattle officials do not comment on personnel moves, Boone said he had heard nothing.

"Not a word, and I haven't heard anything from Adam [Katz, his agent], either," Boone said.

Other than that, Seattle ruined an otherwise flawless afternoon for a second straight day, giving up Damian Jackson's first career two-homer game and a homer to Xavier Nady for a third straight game.

"We played well offensively and defensively in this series," Mariners manager Mike Hargrove said. "But I am sick and tired of seeing our pitchers work from behind in the count. We lost this series because we couldn't get ahead of the hitters."

Hargrove said he would address the matter with the pitching staff in a meeting before the start of the three-game series in Oakland tomorrow.

His team was pitching from behind, and behind on the scoreboard from San Diego's first batter of the game, until Rivera's keepsake homer got it even six innings later.

Jackson, regarded a light hitter with 24 homers in 1,924 at-bats entering the game, put the Padres ahead, where they had started each game of this series.

Seattle starter Joel Pineiro started the light-hitting infielder out 1-2, but Jackson fouled off several strikes, ran the count full, and hammered a centered fastball out to left for a leadoff homer.

"I was going after him. I'm not going to work the leadoff guy with curveball and soft stuff," Pineiro said. "He fouled off some good fastballs, and I threw one that I wanted him to hit because I didn't want to walk him. But I didn't want him to hit it like that."

After Khalil Greene opened the third with a double, Jackson singled him in, then took second on a nice delayed steal that caught the Mariners off guard, and scored on a Mark Sweeney single that made it 3-0.

Jeremy Reed saved Pineiro a run in the fourth when he made his third wonderful open-field diving catch of the week to rob Sean Burroughs of a hit. But Nady crushed a fastball into the third deck down the left-field line to make it 4-0.

Boone got one run back with his homer to left in the fifth, then saved Pineiro more trouble with his diving stop on Sweeney after Woody Williams and Jackson singled in the bottom of the inning.

Boone dove left, and, having twisted onto his back making the grab, flipped the ball with a stiff arm to shortstop Mike Morse.

"It was easier than I made it look," Boone said with a laugh. "The throw, that is. The catch wasn't."

It all seemed to pay off when Boone and Morse singled with two gone in the seventh and Rivera pounded a 2-1 fastball out to left-center to stun the Padres.

"I hit it good and it was a good feeling," the shy Rivera said. "The loss didn't hurt the good feeling. Our team played hard, plays every game hard. The other guys hit homers, too. Stuff happens."

The bad stuff was that Randy Winn led the eighth with a double and was left on third with one out when Adrian Beltre hammered a grounder right at a drawn-in Greene and Richie Sexson flied out deep to right-center.

More "stuff" included Jackson's second homer of the day in the eighth, off a 3-1 fastball from reliever Julio Mateo, to give him three homers for the year and give his team its winning margin.

All of which left Seattle deeper in the cellar and decidedly in the trade market.

Bob Finnigan: 206-464-8276 or bfinnigan@seattletimes.com