The Red Devils have been conscious of managing his game time during the first half of the campaign.
Ibrahimovic was recently handed a four-day break so he could recharge his batteries, following a lean spell in front of goal.
But Old Trafford insiders insist the 35-year-old is now reaching his optimum levels of fitness, and was part of a wider plan to ensure he can cope with the relentless demands of the busy festive period, with games also to come in both the FA Cup and EFL Cup in early January.
Ibrahimovic has kept a constant dialogue with boss Jose Mourinho, who trusts the Swedish striker to listen to his own body and inform United's medical staff of his physical state.
The former Paris Saint-Germain superstar has hit eight goals so far this term and it was announced earlier this week he will be remaining at the Theatre of Dreams for another 12 months.
Ibrahimovic is back and available for selection against West Ham United on Sunday after serving his one-game domestic ban last weekend.