Ian Harkes, Benjamin Siegrist and Lewis Neilson are three of seven players on expiring deals at Tannadice.
The most unlikely of the trio to commit their future to United is No.1 goalkeeper Siegrist with manager Courts admitting the club are having to be proactive with potential replacements.
St Johnstone goalkeeper Zander Clark is a key target for United with the Saints’ No.1’s deal also up at the season end.
Siegrist, during the last 12 months or so, has been linked with clubs in England as well as with Celtic and Rangers. Over the course of the past two campaigns he has proven himself to be one of the best in the country.
Courts has not ruled out Siegrist remaining at Tannadice.
“The club’s discussions with Benjy have been on-going,” he said.
“They are very transparent and open but we also need to monitor activity, not only in Scotland but overseas as well. That is something we are doing regularly.
"We have to be proactive and protect the club’s interests”
Meanwhile, Courts is hopeful of retaining Harkes who has been one of the most improved players in the league this season having “fully responded” to the way United want to play under their manager.
The midfielder, who is currently out injured, has produced some big moments.
Courts said: “He has been one of our standout performers and trains all out every day. He is very well liked within the group and is a really intelligent footballer.
“He is also at a brilliant age and if he was to commit to a new contract at Dundee United then I would see that as a really big breakthrough for Dundee United.”
As for Neilson, talks have “on-going” this year. The 18-year-old has featured nine times this season, including an impressive performance at Celtic and a strong showing in the weekend’s crucial win over Motherwell.
“Lewis has had to be patient and wait for his opportunity," Courts said. “He has made a number of appearances for an 18-year-old centre back.
“He is an exciting young talent.”