Greg Johnson at Shore Capital said: "It's the U.S. opportunity that excites most, with William Hill building a presence throughout the regulated (and growing market)".
But despite another year of major challenges, the major bookmaker finally saw some consistent positive developments coming its way.
Commenting on her departure, Prior said: "I have enjoyed my time at William Hill and believe that the company is in a strong position to take advantage of many opportunities ahead and deliver improved business and financial performance".
The company expects operating profit of between £143m to £148m, thanks to favourable sporting results through the year end. The company said today that during 2019, it made "good progress" towards delivering its long-term strategy to become a "digitally led and internationally diversified business of scale while continuing to embed a culture of responsible gambling".
William Hill has cited strong progress throughout 2019 as it delivers profits ahead of expectation across key markets during a year of transition.
Independent bookmaker BoyleSports has acquired William Hill's chain of 33 shops in Northern Ireland.
Betting companies have become increasingly restricted in the United Kingdom and other European markets such as Italy and Sweden as governments crack down on gambling advertising and betting online. The company pointed out that weakness in online gaming revenue was offset by a strong sports betting gross win margin. Sportsbook revenue was weak, with the firm boosted by a good performance in gaming that was driven by Mr Green.
The US business - which investors are pinning their hopes on for future expansion - experienced "strong growth" in the final quarter and is now expected to break even instead of making losses of up to $20m. As a result, it expects to break even for the US business overall in 2019.
"However, it's the USA opportunity that excites most, with William Hill building a presence throughout the regulated (and growing market)".
Prior's resignation is "a material negative", the analysts said, while also saying the online business "has been turning around for so long it is hard to tell if it is turning around or bogged down".