The Argentine centre half was forced to miss last weekend’s Premier League win away at Crystal Palace through injury.
However, having returned to training at the start of this week, the 31-year-old came on from the bench late in the second half of Tuesday’s 5-1 Champions League win over Atalanta.
And with a hectic schedule of games coming up over the next few few months for Pep Guardiola's squad, Otamendi’s return to action couldn’t have been more perfectly timed.
“After the international break I tried to recover from the pain I had on my back,” the Argentine central defender revealed.
“I had a small injury after playing Everton and I kept on playing in the following games.
“Then I had to stop to recover, but now I’m available.”
Despite the emphatic nature of Tuesday’s final scoreline against Atalanta, the Italians proved testing opponents – especially in an impressive opening 20-minute spell – illustrating why they lie in third place in Serie A.
City will tackle Gian Piero Gasperini’s side again early next month when we travel to Milan’s San Siro for our fourth Group C encounter and Otamendi is expecting another tough test, adding that Atalanta's spirited showing on Tuesday night came as no surprise.
“Yes (they are a good team) - that’s why they’re in the Champions League,” Otamendi added.
“Atalanta are a team that takes a lot of risks. They play good football and they have great players.
“And they had a good game here, but yes, we always try to be clinical when we attack and tidy at the back.
“Sometimes the opponent forces you to defend disorderly, but we always try to be in control.”
The midweek win featured yet more impressive displays from both Raheem Sterling – who claimed an 11-minute second half hat-trick, and Sergio Aguero, whose first half brace gave City a 2-1 half-time advantage.
For Otamendi, the pair’s lethal finishing skills merely served to emphasise once more the potent attacking options at Pep Guardiola’s disposal.
“We know our potential in attack,” Otamendi added.
“When Agüero, Sterling, both Silvas… whoever plays they will have situations and we have to benefit from them, like we did on Tuesday night.”