A central defender on loan from Tottenham, Walkes had spent the opening months of his MLS stint grabbing minutes off the bench here and there. So it was something of a surprise when Walkes not only got the nod, but did so over veteran Tyrone Mears at right back — a position he hadn't even trained at.
Pulling the young Englishman aside, Atlanta captain Michael Parkhurst had to ask: Did Martino tip him off about the start?
"Yeah," Walkes said. "I found out five minutes ago."
Walkes wasn't fazed, logging the full 90 minutes as Atlanta earned a 1-0 victory. Although the 20-year-old is a center back or defensive midfielder by trade, his 6-foot-2 frame, considerable pace and technical prowess add up to an effective MLS fullback.
But while Walkes boasted the tools necessary to make the transition, there's no substitute for experience. Having logged just 10 first-team minutes for Spurs and 66 MLS minutes with Atlanta, Walkes found himself dealing with more internal consternation than his tranquil demeanor would've implied.
"I wouldn't shy away from how I felt — I was nervous," Walkes told Goal. "You just try to push the nerves away because regardless of whatever game I'm going into, whenever I know I'll be playing I always apply pressure on myself to perform."
Walkes hasn't given up the job since, starting six consecutive games — during which Atlanta is 4-0-2 with three shutouts. Earlier this month, United confirmed the club was extending his loan through the end of the MLS campaign.
"He's been a good pro since day one," Parkhurst said. "I think most of the young guys coming over from Europe understand their role. They understand the responsibility, they know that chances can be tough to come by and you have to be ready for your opportunity — and he was."
Born in the south London borough of Lewisham, Walkes joined the Spurs setup in 2013 and made his first-team debut in an EFL Cup clash with Gillingham last fall. But with Walkes not yet ready to contribute to Mauricio Pochettino's side on a regular basis, the club explored loan options last winter.
Enter Atlanta, an MLS expansion side run by former Tottenham executive Darren Eales. Even though Walkes had opportunities to potentially go on loan in England or elsewhere in Europe, the chance to broaden his horizons stateside proved enticing.
"They just said the opportunity was there for the taking, and I could have a few weeks to think about it and just get my mindset around it because that's a big step," Walkes said. "It's not like going away in England where you might be a few hours or even 20 minutes, 30 minutes away from home. But my decision was made in a few days."
Making the jump to MLS presented a gamble in its own right, and joining an expansion side upped the ante. But United quickly put Walkes' mind at ease.
Martino, the former Barcelona and Argentina manager, brought credibility to the technical staff. The likes of Paraguay playmaker Miguel Almiron, Venezuela striker Josef Martinez and Argentina prospect Hector Villalba made for a talent-laden squad. And a raucous fan base embraced the club from the start, selling out seven straight matches for an MLS-best 46,698 fans per game.
"To be a part of an expansion team in a league which is growing so quickly with the quality of players that are here, it would be very hard to say no at this moment in time," Walkes said. "It was something that didn't require much thought.
"You don't know what to expect, but just from how everything was being handled you could tell the team was being built to be a great team from the beginning."
With longtime MLS standout Parkhurst in central defense alongside River Plate product Leandro Gonzalez Pirez, playing time was hard to come by for Walkes in his preferred position. But after starting the first 15 matches, 34-year-old veteran Mears started to lose his grip on the right back role.
While Walkes still is learning the situational subtleties of playing right back — in particular, picking the right moments to venture forward — his swift adaptation to the position has served as an endorsement of his soccer IQ.
"He's just a very reliable defender," Parkhurst said. "You take his age for granted sometimes because he seems more experienced. He just knows tactically where to be and when. Also getting out and closing guys down he's a good defender. He's got the athleticism to stay with some of these dynamic wingers we have in the league, and obviously in the air he's very good as well."
As the new Premier League campaign gets underway, Walkes makes every Spurs match appointment viewing. And the Tottenham technical staff has continued to keep tabs on Walkes, texting the player to get his self-evaluation after matches.
Once Walkes' loan ends — after a lengthy postseason run with Atlanta, if all goes to plan for Martino's men — he's scheduled to return to Tottenham. The next step then remains a mystery, whether it's fighting for minutes at Spurs, returning to MLS or going out on loan elsewhere.
"It's just wherever I can play football — that's always going to be the key," Walkes said. "Things have been wonderful here, so my main focus isn't really going past the remaining games and the playoffs."
If Walkes' MLS stint ends up being just the single campaign, he'll have no regrets about the decision to take his development stateside. In his mind, it's a gamble that already has paid off.
"It's a great quality of football," Walkes said. "There's been a few people who have criticized it, and that's just a lack of knowledge really because this league is a great league with very good players. This league is only expanding, so I don't see why any player wouldn't want to come here at some stage of their career because it's amazing."