Both defenders missed Saturday evening’s Premier League win over Crystal Palace, providing further injury concerns for the Champions’ defensive backline.
Guardiola opted to field midfielders Fernandinho and Rodrigo in the central defensive positions at Selhurst Park to good effect, but the Catalan boss explained Walker and Otamendi are nearing returns.
“Kyle is getting better,” he said. “Both were training yesterday for the first time.”
City host Atalanta at the Etihad Stadium in Matchday Three on Tuesday night, seeking to cement our place atop the group.
Sitting third in Serie A, the Italian outfit have impressed this season, scoring 21 goals already but conceding 13 with Gian Piero Gasperini’s side also suffering defensive woes.
Guardiola hailed La Dea’s start, deeming the Italian side ‘a joy to watch’.
“In this match, both teams are very brave, trying to impose their game,” he added. “We will have to adapt to what they decide to do; they will have to do the same.
“What I said about Maurizio Sarri, I could say about Gasperini. I was lucky enough to meet him before.
“Having seen what Atalanta did last season and this year, it’s incredible. It’s as if they had won the Premier League with a big team.
“It’s a great joy to watch his team play. They’re brave, they respect their supporters and that’s the way they play.
“It’s unusual – they take quite a few risks and I’m sure they’ll play that way.
“I hope it will be very open. Atalanta scores a lot but sometimes they concede – we are the same.
“Hopefully, it will be an interesting, lively match.”
With City having secured two wins from two so far in Group C, Guardiola was also asked whether he feels his side have what it takes to go on and win the competition.
“I’m very confident and have full trust in my team,” he stated. “I know a lot of other teams are very strong and can win the Champions League.
“The Champions League will be won in the box. So far, we haven’t been very strong in the box.
“We have made a number of mistakes we should not make at this level. We have created a lot of opportunities but scored very little. We’re very good at defending.
"Scoring in the right moment is what we have to work on so we are able to do it in a match.”