The iconic former centre-back's career was coming to a close after 16 years as a Fox, but he nonetheless played a crucial role in an excellent run to a third final in four years for Martin O'Neill's men.
Despite battling against injury for much of the 1999/00 season, Walsh was in the thick of the action for one game in particular - a dramatic fifth round clash with First Division side Fulham at Filbert Street.
Paul Peschisolido fired the Cottagers in front before, following an uncharacteristic error from Walsh himself, Geoff Horsfield put Paul Bracewell's visitors into a two-goal lead with 15 minutes to play.
In typical fashion, though, Walsh made amends by first laying up Ian Marshall to get one back for Leicester before firing a superb rocket past Maik Taylor to restore parity on the scoresheet on 87 minutes.
More drama followed in extra-time, with Chris Coleman edging the west Londoners back in front, but there was Marshall again to send the tie to a penalty shootout in front of the old Double Decker Stand.
While Walsh missed the final against Tranmere Rovers a month later, that night under the lights at Filbert Street - ending in a 3-0 shootout win - stands out among his fondest memories in a Leicester City shirt.
"I was coming to the end of my career and it was getting a struggle in training and there were injuries appearing as I’d had a lot of surgery on my knees," he told LCFC TV earlier this year.
"That was a massive game for us and we didn’t really play that well in that game. We were up against a good Fulham team, I think Horsfield played, Peschisolido played and it was a real backs to the wall job.
"But in the end, I just remember playing a lot of long balls in that game and we had to force the game. It was at home at Filbert Street, in front of our own fans, and we were 1-0 down.
"And then I made a horrendous mistake, but through an injury I’d got, I pulled or tweaked my groin, and I played on. I stopped knocking any long balls and I was looking inside.
"I remember seeing Gerry Taggart, so I tried to play it to him, [but] it was intercepted by Peschisolido, round the ‘keeper, 2-0, [and] we’re out of the cup as far as I was concerned, without a doubt.
"It was my fault, so for about two minutes, I just thought: ‘Right, I’ve got to do something about this’. And every chance I got to go upfront, I went upfront, and I got an important header, an assist for Marshall.
"Then minutes later, there was an opportunity. Marshy returned the favour with a knock down and then I hit a volley like I've never hit one before... and my groin felt great, I can tell you!
"So, I had gone from a villain to a hero, in a sense of getting us back in the game to win the game. Again, it was won on penalties, so we’d scraped through and that was one hell of a game.
"My memories of that goal is one of my best memories that I had. Obviously, I had the Derby final, [which] was a huge thing for me, no. 1 I’d say.
"Those goals – and the one against Arsenal – and the one against Fulham, in a game that important, was a winner for me."
Fans who once filled the four uneven stands at Filbert Street view Walsh as one of the most iconic players in the Club's recent history - and it's hard to disagree with them.
That strike against Fulham was followed by classic celebrations as 'Walshy' dived into the lower tier of the Double Decker Stand, fists clenched, screaming in delight, in scenes Foxes fans will never forget.
"I just remember Marshy heading the ball down and I let the ball bounce once. It just bounced nicely and I kept my eyes on the ball and just hit it as hard as I could with my head down," he said.
"It just screamed into the net! So, in front of the Kop, it was just amazing. It was just the thing I needed after a mistake and [going] right into the fans, I’ll never forget just jumping into the fans.
"I knew at that moment that we’d go on and win from there, so it was, like I say, a special moment."
Sharing such moments together bonded Walsh tightly with the Blue Army and the former Foxes captain admits he still pines for Filbert Street, City's home for 111 years until 2002.
"I remember signing in 1986 as a 21-year-old, coming down to Leicester, and just walking round the ground in the early stages, when we were in the First Division," he explained.
"I had 14/15 years playing at Filbert Street and I can tell you, you get fond memories and a relationship with the ground and the people attached to it.
"The surroundings, the Bentley’s roof, with everyone standing while you’re playing. I can remember, still, every time just looking up at them [on] Bentley’s roof, about 20 of them all stood on a roof.
"The Kop itself, with the Double Decker above it, was great because I scored so many goals in the end in front of them and you get no better feeling from that.
"My association with the fans grew and grew until we had a really good bond, so it was special. Even just walking out on the pitch, for me, was quite emotional and your warm-up and things like this.
"When I crossed that white line, that was it, you just fought as hard as you could and those memories of all those games are very special to me.
"I generally missed the other cup games games after that, which led up to the final, which was annoying because I’d ripped my groin and I knew I had quite a bad injury.
"Now, obviously straight after that game, I didn’t play for a few games, and was trying to get myself fit because I wanted to play a part in the semi-finals and try and get us to the final.
"Obviously, I was not fit, so it was just one of those things that I had to get on with. I think I was sub in the first one at Villa Park and, again, for me, it’s ideal playing away first.
"I really did used to think that you have an advantage if you’re playing away first, if the goals came into play, and so we’d got a great result.
"[We] got a clean sheet… ideal, away from home, perfect. So, to go into a second leg, I was very confident then and, obviously, I missed that.
"I had to watch the game and Matty Elliott, I can just remember him back peddling with his arms.
"I can still visualise him, just before half-time I think it was, when he scored that goal… it’s just a memory that sticks in of him back peddling and [it was] a brilliant header.
"We were there again, so what an achievement. When you’re looking at that decade, it was seven Wembley appearances I think. Four play-offs, and a third League Cup Final. An amazing decade."
20 Years On: Leicester’s League Cup Triumph can be viewed now, for free, on LCFC TV.