Robbie Neilson believes other teams would have been extremely keen to sign Lee Nicholls before the keeper signed a new contract at MK Dons.
The 25-year-old put pen to paper on a new two-and-a-half year contract on Thursday, with his previous deal set to expire next summer.
And with the January transfer window approaching, boss Neilson said Nicholls would certainly have been on others' shopping list next month.
He said: "I have no doubts there were other teams looking at Lee and looking to take him but he has committed his future here, now he can settle down and play as well as I know he can.
"It affects players. It's important they're fully concentrated on their form, not what's going on behind the scenes.
"We're delighted to sign him up."
Nicholls was the number two behind David Martin when Neilson arrived at Stadium MK last December. But after an injury to long-term first choice Martin in April, Nicholls stepped in and kept his place until the end of the season, with Martin leaving the club at the end of the season.
"We gave him the opportunity this season and he has done well," Neilson continued. "There's a lot of progression to come, but for the age he is and the experience he's getting, he's a huge asset to the club.
"When I first came in, David Martin did the majority of the season but towards the end, we felt it was the right time to get Lee in and give him a number one shot - it was up to him to tkae it.
"He has a decent start to the season, but he and Healdy have a lot of work to do to get to the level I think he can get to but as long as he keeps working hard, he has a great chance.
"He's level headed and a fantastic shot stopper. He's good with both feet, he needs to work on his decision making a little bit but that comes with experience. When you put a young keeper in, they learn from mistakes, and that's why not many people do it. But I think he's a big asset and I'm really glad he's sighted up for another two years."