Central defender Philipp Wollscheid had already agreed a permanent move from Bayer Leverkusen after impressing while on loan last season, while deals for FC Midtjylland goalkeeper Jakob Haugaard and Hannover 96 striker Joselu duly followed.
Hughes is looking to sign more players over the summer though, as he looks to improve on the club’s ninth place finish last season.
“We have managed to bring both Shay and Marco in over the past 24 hours which is really pleasing and hopefully another one will be done and dusted over the next day or so,” Hughes told the club’s official website on their pre-season tour of Singapore.
“We are pleased that we have managed to get a fair bit of our business done early, because we see benefits to that, but there are still two months remaining and we will keep looking for options that we feel will improve us.
“We have lost out on a couple and been frustrated with one or two other targets but we are in there right now actively looking, so hopefully one or two more drop for us. We certainly have a few irons in the fire.”
Watch Stoke in pre-season action against Everton in the Barclays Asia Trophy, live on Sky Sports 1 HD next Wednesday from 10.45am.