"They expect a lot of me, so I know I really need to step up and just go out there and dominate and pitch and go after them," said the 22-year-old right-hander.
Manager Lloyd McClendon delivered a pretty succinct message to the youngster upon his arrival in Oakland, telling him he'd pitch out of the bullpen initially and if he wanted to progress to a bigger role, then start showing he deserves that opportunity when he gets his chances.
Walker pitched well enough Monday that McClendon is at least pondering the possibility of moving him into the rotation in Chris Young's spot Saturday in Texas if he feels Young isn't fully healthy after the veteran lasted just two-thirds of an inning Monday in his second straight abbreviated outing.
"I saw his potential yesterday," McClendon said prior to Tuesday's game with the A's. "Obviously he pitched extremely well. It showed what he's capable of doing. We need to get him to the point where he's consistent every time out with that."
Is there time to make up for a mostly lost season for the youngster?
"Definitely," said Walker. "Whenever they give me the ball, I just have to go out there and pretty much do what I did [Monday]. Just keep going out there and pitching good."
Walker said he felt better in his last five starts in Tacoma since simplifying his approach. And his goal now is pretty simple as well. Get the ball, get outs and show what he can do. And if he does enough of that, he might well wind up with a bigger role in the closing weeks as the Mariners piece together their pitching for a run at the postseason.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.