Hammers captain Rice berated the Spanish official during a foul-mouthed rant in the tunnel after Thursday evening’s semi-final elimination at the hands of Eintracht Frankfurt.
The Premier League club intend to view the referee’s report before commenting on the incident, while UEFA could yet sanction the England midfielder.
But manager Moyes – who does not believe Rice’s complaints to be genuine accusations and feels nothing untoward occurred – swiftly dismissed suggestions of internal punishment.
“Not a chance – not on my watch anyway,” said the Scotsman, whose team suffered a 3-1 aggregate loss.
“If UEFA punish him that’s down to them but not on my watch.
“Declan’s the captain, Declan’s fully behind the team and totally committed – like the manager, like the captain.
“We are all fighting for the same thing, which is to be winners here, and Declan is part of that.”
Rice’s remarks to Manzano were captured by American TV company Fox Sports, with footage circulating on social media.
“Ref, ref, it’s so poor, all night, it’s so bad,” said the 23-year-old.
“How can you be that bad, honestly? You’ve probably been f****** paid. F****** corruption.”
West Ham had Aaron Cresswell dismissed with only 19 minutes on the clock at Deutsche Bank Park and were beaten 1-0 on the night after Rafael Borre increased the German hosts’ 2-1 first-leg lead just seven minutes later.
Full-back Cresswell, who pulled down Jens Petter Hauge as he attempted to go through on goal, was initially shown a yellow card but it was upgraded to a red after a video assistant referee review.
Moyes was also sent off during the match – for kicking a ball at a ball boy – and felt aggrieved at the standard of officiating.
Yet he downplayed the seriousness of the post-match flashpoint, insisting it demonstrated the passion within his squad.
“You might say it is a headache; I say it’s someone showing how much he cares,” he said.
“The whole team was devastated we didn’t get through. We found it really difficult circumstances.
“We felt as if we had been treated quite badly overall and that is what happens.
“If you know about football, everybody is emotional so unless you’re in the heat of it sometimes people don’t understand how it feels.
“We had a group of players who were really connected, trying to win the game and felt it was very difficult under lots of different circumstances.”
Defeat for West Ham denied them a first European final since 1976.
A club spokesperson said: “The club is aware of the video circulating on social media but will not be commenting further until the referee’s report from the UEFA Europa League semi-final second leg against Eintracht Frankfurt has been considered.”
Frankfurt will take on Rangers for the trophy on May 18 in Seville.
Meanwhile, the seventh-placed Hammers must quickly set aside their disappointment as they focus on European qualification for next season, beginning with Sunday’s top-flight trip to relegated Norwich.