Walker inherited four horses from trainer Lee Freedman as the latter is set to return to Gold Coast to continue training in March. They are the dual-Cup winner Mr Clint (2018 Singapore Guineas and 2019 Singapore Gold Cup), who incidentally becomes his current highest-rated horse at 98 points (three points more than Sacred Rebel), Augustano, Super Invincible and Nationality.
Both Super Invincible and Nationality turned up in the third trial on Tuesday morning, in which Super Invincible was given an easy spin around the track by race-rider Hakim to finish nine lengths in seventh behind stablemate Nationality (Jerlyn Seow, No 1 Emergency Acceptor in Saturday's race), who ran second to Nimble (Troy See).
"We just decided to give him (Super Invincible) a quiet trial as he's running on Saturday," said the three-time Singapore Champion trainer, who is now second on the premiership on 11 winners, two behind Michael Clements.
"The owners (Joy N Happiness Stable) approached me to train their horse after Lee announced that he's leaving. He came to me on February 15 and so we haven't had him for a long time.
"He was in great condition when he came over, credit to Lee. We're still learning about him, but he seems to be in good form.
"He looks more of a 1000m horse to me, so the 1100m is a bit of a concern.
"Hopefully, he draws an inside barrier and he doesn't have to spend too much effort from the front. And with Hakim's three-kilo claim (carries 55.5kgs after claim), he stands a good chance.
"Nationality has trialled two times for me, running first two weeks ago (February 9) and second this morning.
"I'm happy with him, but he didn't get in at the ballots. Let's hope he can get a run on Saturday, and if he does, Jerlyn will ride him.
"We removed the winkers at both his trials because we wanted to save him for the races, so he will wear them when he races."
The six-year-old son of Commands was slow out of the gates in the field of nine, but Seow bustled him up in the backstraight to come onto the outside of leader Nimble, where he chased him to the line with stablemate Axel (Saimee Jumaat) in hot pursuit in third.
Super Invincible was handy at first, but only ambled along in the straight to finish down the field, though still about 10 lengths ahead of Walker's fourth horse Ronaldo's Dream (Vlad Duric), who came in last.
The four-year-old son of I Am Invincible has won twice over the 1000m and placed three times in six starts thus far. He last ran third to Sacred Rebel over the 1100m on the Polytrack in a Class 2 race two weeks ago, albeit with a lightweight of 47kgs with Freedman's apprentice Iskandar Rosman on board.
Walker has a third runner, Red Rover, in the highlight race on Saturday. Though kept to sprint races prior, the six-year-old gelding was first tested over a mile in a Kranji Stakes C race on Polytrack in January but ran last to Vittoria Perfetta.
"We tried him over the distance but it did not suit," said the New Zealander who sends out 18 runners this Saturday, of which five are Emergency Acceptors.
"He's been disappointing. He's more of a Class 4 horse. The field looks too strong for him this time."
The O'Reilly bay will carry 54kgs and Walker has entrusted the reins to jockey Saifudin Ismail.