Robinson, 23, was one of two young hitters obtained in the Erik Bedard trade on Sunday. He played just three games for Triple-A Tacoma before getting called up by the Mariners in time to play in Friday's series opener against the Angels.
With the Mariners now full speed ahead in their youth movement, Robinson started in left field on Friday and made a spectacular home-run-saving catch on a ball hit by Torii Hunter in the third inning of a 1-0, 10-inning loss. He also went 1-for-3 at the plate, with a single off Jered Weaver in the sixth inning, while batting ninth.
"At the time of the trade, everything was going 100 mph," Robinson said while sitting in the Mariners' dugout prior to Friday's game. "I was thinking about a lot of things, like missing my [Dodgers] teammates that I've been with for six years.
"Then I landed with a great group of guys in Tacoma that I was starting to get comfortable with. A day later, I'm over here. This is pretty fast and pretty amazing. It's the best four days of my life."
Robinson will become the 13th rookie to play for Seattle this season, the most in the American League. He'll also be the ninth Mariner to make his big league debut this season, the most in the Majors -- joining Dustin Ackley, Blake Beavan, Josh Lueke, Michael Pineda, Carlos Peguero, Kyle Seager, Mike Wilson and Tom Wilhelmsen.
Robinson is regarded as a leadoff-type hitter and center-field candidate, but the 5-foot-10, 200-pounder will share time in left field as well, while batting lower in the lineup initially.
He played center field in his three games with Tacoma since the trade, going 1-for-9 with three walks. Prior to his acquisition, he batted .293 with 26 home runs and 71 RBIs in 100 games with Albuquerque, the Dodgers' Triple-A team in the Pacific Coast League.
Manager Eric Wedge said Robinson, Casper Wells and Mike Carp would share time in left field and in the designated-hitter spot, while Robinson can also fill in for center fielder Franklin Gutierrez when needed, as well.
"We'll mix and match with our young kids in left field, give Gut a day from time to time in center and, obviously, there's the DH spot, too," Wedge said. "With Carp being able to play some first base, that helps us out a little -- especially with [Justin] Smoak day to day, right now. So we'll work to get them all in there."
Robinson stole 38 in bases in Double-A ball in 2010, and 47 while splitting time between Double-A and Class A in '09. But he had become more of a power hitter and less of a runner this year with Albuquerque, with eight stolen bases in 14 attempts.
"I don't know," he said of the change. "This year, I started off in the [seven-hole], had a couple guys on base and started doing a little better hitting there. I started hitting with guys in scoring position. I looked up and, a month into the season, I was batting fifth.
"I'd been batting first or second or eight my whole career. For me to be batting fifth, it was a different result. I got a lot of different results this year. It was kind of weird. But I can still run."
As a Los Angeles native, he'll be making his Major League debut in his hometown. Angel Stadium is about 35 miles south of Crenshaw High, where he graduated in '05. He bought tickets on Friday for eight family members, who'll enjoy his debut almost as much as he will.
"This is the longest and biggest dream I've ever had in my life," he said. "I can't even express how excited and everything I was when I got the call. I'm still smiling about it. I think I've got about six hours of sleep in four days. I couldn't even play my video games, I was so excited."
Robinson is an alumnus of two MLB programs -- the Urban Youth Academy and the RBI program, both designed to help urban and minority youth get baseball experience, and life skills and educational opportunities.
He recognizes what this chance means and what he wants to do with the opportunity.
"Embrace it," he said. "Your first only comes once, so I'm going to remember this day. I'll remember all you guys, right here. One of my friends even told me to pick up a piece of the grass and put it in [my] pocket. But all I want to do is be Trayvon. Be Trayvon and just play. That's it. Play hard."