Celtic defenders Charlie Mulgrew and Emilio Izaguirre have both agreed contract extensions, keeping them at the club until 2015.
Izaguirre, currently sidelined with a broken ankle, was last season's player of the year in Scotland.
"This is a great honour for me and something I was very happy to do," said the Honduran full-back, who signed a four-year deal last August.
Mulgrew returned to Celtic last season, after spells with Wolves and Aberdeen.
"I enjoyed last season, and in particular lifting the Scottish Cup," Mulgrew told the club website. "But we were all disappointed that we weren't able to add the league title as well.
"That's something we are determined to do this year, and everyone at the club will be working as hard as we can to try and achieve that."
Izaguirre is now targetting an early return from the injury he picked up against Aberdeen which was expected to keep him out for six months.
But the 25-year-old is keen to return to training.
"My only focus is to get back fit and playing again for Celtic," he said.
"I hope to re-join my team-mates as soon as possible and again work hard on bringing success to our fans.
"This is what we all want to do, the players, the manager and the staff, we will work together and united throughout the season to try and achieve this."
Celtic will find out on Tuesday if they they may yet earn a reprieve and a return to the Europa League groups stages as a result of Sion's row with Fifa over the eligibility of five players in their squad.
The Parkhead club's defeat to the Swiss Cup champions came just days after a Scottish Premier League defeat to St Johnstone, but Mulgrew says the players remain positive.
"I know that recent results have been very disappointing, and we want to get back to winning ways as soon as possible, starting with Sunday's game against St Mirren," he added.
"The support all the players and the management get from our fans is incredible, and we want to reward that in the best way possible, by ensuring that the league title returns to Celtic Park."