Morningstar previously had a "silver" rating on the Trans-Tasman fund, which has delivered total returns of 17.8 per cent over the past three years.
The rating will be updated following a formal meeting between Morningstar and Milford.
Morningstar analyst Kathyrn Young said there was a risk of capital leaving the fund following last week's changes.
"I wouldn't characterise the risk as excessively high, but it's certainly a possibility," Young said.
If outflows did occur, Milford could be forced into selling down holdings to make repayments.
In that scenario, the fund's risk profile could increase because the higher liquidity holdings would get sold first, leaving the fund more exposed to illiquid assets, Young said.
She said Morningstar had "high conviction" in Gaynor's abilities, but the Trans-Tasman fund had a different style to the Active Growth Fund.
"We want to know how this fits in with [Gaynor's] other responsibilities," Young added. "Obviously he's a key figure with the firm."
Gaynor told the Business Herald last week that recent changes within Milford had reduced his management responsibilities, leaving him with more time to focus on investment.
Milford managing director Anthony Quirk said the firm had seen "net in-flows" across its funds since last week.
"In terms of the Trans-Tasman fund, with Brian you've got a very astute investor in charge there," Quirk said.
He said the risk of capital outflow was a "hypothetical situation".
"From our point of view we're very happy with the client reaction since the settlement and haven't seen any evidence of that concern," Quirk said.
A Milford portfolio manager is still facing enforcement action from the FMA and was placed on extended leave on Thursday, the same day as the settlement announcement
The company has declined to confirm whether Warminger is the individual still under investigation.
