Johnston set to make changes Queen of the South manager Allan Johnston looks set to freshen up his in-form side for the clash with Dundee United following a hectic period of games. The attacking threat of Daniel Orsi and Gavin Reilly look set to start after substitute roles in the 3-0 victory over Brechin on Saturday, with experienced campaigner Derek Young also in line for a return after dropping out of things altogether following the Doonhamers' Ramsdens Cup success against Rangers. Johnston said: "We have had a few big games recently so hopefully we can be fresh again and ready to go for what will be a really tough tie. "Dundee United are a quality side and we need to ensure that we match the tempo they will look to impose on the game." Dundee United midfielder Stuart Armstrong believes the settled environment of Tannadice is the perfect launchpad for his career. The 20-year-old today extended his contract until May 2015 after establishing himself as a first-team regular with 47 appearances. Armstrong, who was joined by 22-year-old full-back Keith Watson in prolonging his stay, said: "I want to establish myself as a first-team player and it's a great club to try to make your way in the game. "I'm happy here, the fans are great and it's a good chance to develop as a player in a competitive league like the SPL so it was an easy option to sign on. It was a good choice, I think." Watson and Armstrong both started Saturday's 3-0 defeat by Hearts along with fellow youth-team graduates Johnny Russell and Ryan Dow, while 16-year-old Ryan Gauld came off the bench. Armstrong feels the number of familiar faces in the team can help him adapt. "We all know what we are capable of, you are comfortable when you know what other players are around you and have had them around you for a while," the Scotland Under-21 international said. "It puts you at ease when you know what they can do. "I've spent most of my career here, and a couple of years at first-team level, so it definitely feels like home. "I'm very comfortable amongst the staff and the boys who have stayed here with me. "Young players like Ryan Dow, Scotty Allan when he was here, Ross Smith and Dale Hilson have all come up with me so it's good to have the boys you have played with at under-19 level here to help you." Queen of the South are unbeaten this season and have knocked Hibernian and Rangers out of cup competitions, but Armstrong welcomes the chance to make amends for Saturday at Palmerston. "It's probably best to have a game so soon to bounce back after the disappointing game against Hearts and we are definitely looking to do that," he said.