Willock was once described as a 'very interesting player' by Arsene Wenger during his time at Arsenal, but over the last couple of years the Englishman has struggled to make the jump to the big time, only managing to feature for Benfica's second team where he scored 11 goals in 34 Segunda Liga matches.
The forward has represented England at Under-17 to Under-20 international level, scoring six goals in 41 appearances, and is looking for first team football to help progress his career.
Huddersfield and Stoke find themselves 20th and 21st respectively in the second tier, while the Potters only sit above the relegation zone on goal difference. Therefore, both sides are looking for January reinforcements to help turn the tide.
Stoke and Middlesbrough have already been rumoured to be courting Rangers' Northern Irish winger Jordan Jones, but the former may look to Willock as an alternative to that deal.
Given West Brom's success this season, currently leading the fight for automatic promotion, it would appear that the only first-team opportunities Willock will get will require him to move away from the Hawthorns.
The Benfica man will be hoping his career follows a similar trajectory to that of brother Joe, who is currently making progress in the Arsenal first team.