"Giroud with his experience, he needs to set the barrier very, very high which he's done", Walker told Ian Stone's Comedy Breakfast (weekdays 6.30am-10.30am).
The Premier League giants are bidding for a first trophy under the Italian after losing last month's English League Cup final to Manchester City, and hoping to secure qualification for next season's Champions League.
Teenager Hudson-Odoi got on the score sheet before the final whistle, using his speed to outrun the Dynamo defence on the counter and easily beat Boyko to make it five goals on the night for Chelsea.
Meanwhile, Eden Hazard is one of several first-team stars who should come back into the starting XI as Chelsea continue their pursuit of a top-four finish.
" "[The draw against Arsenal is] a hard but very fascinating challenge for us, for the club and for our fans.
"I thought he was terrific", Walker said.
Chelsea Confirmed lineup vs Dynamo Kyiv: Hudson-Odoi, Loftus-Cheek...
"He's in the area, in the six-yard box more often than most centre forwards you see these days".
"I have been through a lot of tough moments in my career".
Giroud's triple took him top of the overall goalscoring charts for this year's competition, as Chelsea raced into the quarter-finals with a 5-0 win in Ukraine and an 8-0 aggregate scoreline.
"Of course, an Arsenal final sounds good from the British side of things. I had to take it slowly but I'm building up nicely".