OAKLAND -- More than 15,000 fans have RSVP'd to a Mariners invitation for a free shirt for those who register in advance to attend Monday's Opening Day viewing party at Safeco Field, Mariners vice president of marketing Kevin Martinez said on Saturday.

Fans can come to Safeco Field to watch the Mariners' opening game in Oakland on the gigantic new center-field video screen, which will be the largest board in Major League Baseball.

Gates will open at 6 p.m., so fans can check out some of the park's new additions, including the new Edgar's Cantina down the left-field line, as well as the new fences and the big screen that will show the game starting at 7:07 p.m.

Admission is free and parking will also be free in the Safeco Field and CenturyLink garages, as long as space is available.

Fans who RSVP online by 5 p.m. PT on Sunday will receive a voucher for a free "True to the Blue" T-shirt. The RSVP can be linked to on Mariners.com.

The event is open to anyone who wants to attend, but only those who RSVP will get a T-shirt.

"This is the first event of its kind here at Safeco Field," Martinez said. "There are so many new aspects of the ballpark. The open house will give fans a chance to see what they can look forward to all season. From Edgar's Cantina and Home Run Porch, to the expanded 'Pen in center field to the new field dimensions to the video screen, fans will have plenty to explore and enjoy on Monday and throughout the season."

Martinez is among those who've gotten a sneak preview of the new big screen and he says fans are certain to enjoy the high-definition images and ability to show full-screen replays as well as divide the board into smaller sections.

"I was struck by the resolution," Martinez said. "The clarity of the video and graphics on the screen really are incredible."

Mariners set club spring record with 58 homers

SEA@COL: Smoak hammers a solo shot to left in fifth

OAKLAND -- With home runs by Kendrys Morales and Justin Smoak in Saturday's 4-3 victory over the Rockies in Salt Lake City, the Mariners finished their spring with a club record 58 homers. They hit at least one long ball in 32 of their 33 games and led all Major League clubs this spring.

Only one MLB team in the past 20 years hit more spring home runs, with the Cubs ripping 62 in 1999. That club wound up 14th in the Majors in homers during the regular season, led by Sammy Sosa's 63, after he hit 12 in the spring.

Left fielder Michael Morse didn't go deep in Saturday's game, his 0-for-2 day leaving him at .357 for the spring. But Morse led all Major Leaguers with a 1.332 OPS and nine home runs, the most by any Cactus League player since Barry Bonds hit 10 for the Giants in 2003.

Morse also hit nine homers in the spring of 2011 for the Nationals before totaling 31 in the regular season.

Morales, the other primary power hitter acquired in the offseason, cranked his seventh home run of the spring in the fourth inning and Smoak added his fifth in the following frame. Morales finished the spring tied for the fourth-most homers in either the Cactus or Grapefruit leagues.

While the Mariners played more games than usual this spring, their home runs per game average of 1.76 was also a team record, breaking the 1.59 mark set in 1999.

Manager Eric Wedge is pleased with the direction of the entire offense heading into Monday's opener against the A's.

"We've got some good young hitters that are getting better and some veteran hitters that are proven," Wedge told reporters in Salt Lake City. "When you put it all together it's a nice mix for us and you saw a little bit more of that today."

Final roster decisions coming Sunday

Bay working hard to make the Mariners roster

OAKLAND -- The Mariners made just one roster move on Saturday, and that involved Minor League catcher Ronny Paulino, so the team will apparently wait until Sunday's noon PT deadline to announce its final 25-man roster.

Paulino was released from Minor League camp, having already been sent down on March 15 after hitting just 1-for-14 in the initial weeks of Cactus League play.

The club still officially has 30 players on its Major League Spring Training roster, so five cuts need to be made. But four of those -- pitcher Danny Farquhar, catcher Jesus Sucre, infielder Brad Miller and outfielder Endy Chavez -- were just awaiting the conclusion of spring games before being sent down.

Manager Eric Wedge has said the only remaining roster battle was between Jason Bay and Casper Wells, though even that decision seems to be merely a formality as well.

Bay accompanied the team to Salt Lake City and played in Saturday's finale and is expected to get the job, while Wells was left behind in Peoria to play Minor League games this weekend.

Wells is out of Minor League options, so he'll either need to be traded or released by Sunday's 25-man roster deadline. The club wanted to wait until the deadline in case of an injury in the final game, or to leave the door open for a deal of some sort.

The Mariners will hold a 2 p.m. workout in Oakland on Sunday in their final preparation for Monday night's opener against the A's.

Worth noting

• Saturday's 4-3 win over the Rockies improved the Mariners' final spring record to 22-11, the second-most wins of any Major League team behind the Royals (25-7-2). The 22 wins broke Seattle's club record of 21 set in 1994.

• Smoak finished up a torrid spring by going 1-for-4 with a home run on Saturday. Smoak hit .407 with eight doubles, five home runs and 15 RBIs in 19 games and had the fourth-best OPS in baseball this spring at 1.251.

• Catcher Jesus Montero also pulled his average up to .400 by going 1-for-2 with a triple. He totaled six doubles, one triple, two homers and 11 RBIs in 16 games.

• Former Mariners first baseman John Olerud had his No. 18 jersey retired by Washington State University on Saturday in a ceremony in Pullman, Wash. Olerud was the Baseball America College Player of the Year for the Cougars in 1988 when he hit .464 with 23 home runs and 81 RBIs and also went 15-0 with a 2.49 ERA as a pitcher.