The club announced Tuesday that Caldwell has signed a deal that will keep the Scottish international defender in Toronto through the 2015 season. The permanent contract comes at the end of his loan from England's Birmingham City.
"Any club needs stability to move forward and be successful," Caldwell said after practice as Toronto prepared to host the rival Montreal Impact on Wednesday. "We certainly need to settle on a balanced team and give the people here every chance to be successful."
Toronto has been a team in constant flux in Ryan Nelsen's first year as manager as he tries to figure out how to build a winning culture with a team that finished with a league-worst 5-21-8 record last season.
Over 20 players have been jettisoned from the team this season. The latest was 25-year-old centre back Logan Emory, who was cut loose last week.
The final results for Toronto (2-8-6) haven't been overly favourable this season as the team finds its identity, though it did enjoy a modest three-game unbeaten streak before a hard-fought 1-0 loss to Real Salt Lake on Saturday.
The Impact also enter Wednesday's game coming off a weekend loss after surrendering a stoppage-time goal in a 4-3 defeat at home to Colorado — their first home loss of the season.
But the similarities stop there. The Impact (9-4-2) have been a revelation in their second season in the league. They lead the Eastern Conference standings and seem to be a lock to make the playoffs.
The teams have met once in league play this season, with Montreal edging Toronto 2-1 at their home opener at Olympic Stadium.
Toronto beat Montreal 2-0 in the opening leg of their Amway Canadian Championship series at BMO Field, but the Impact decisively won the return leg 6-0.
Daniele Poponi, who scored twice for Montreal in the loss to Colorado, said the Impact is eager to put that game behind them with a win at Toronto.
"I think a quick turnaround after a performance like that is good because we have a chance to come out and change the morale right away, trying to win another game," Poponi said. "Toronto is a good team, we know they have a strong team physically. But if we play our game, we should have success."
"It's important when you lose a game that. . . now you turn a page," added Impact coach Marco Schallibaum.
Caldwell, 32, will be tasked with keeping Montreal striker Marco Di Vaio in check. The centre back has started in six matches for Toronto. He spent the past two seasons with Birmingham where he made 90 appearances and scored two goals in all competitions for the club. He has also earned 12 caps for Scotland in international play.
"I'm excited about the challenge," Caldwell said. "I've seen (Di Vaio) play a number of times. He's a top-quality player and he's scoring a lot of goals so it will be a tough challenge for us defensively. We have to make sure we're solid and we keep their chances to a minimum."
While Toronto manager Ryan Nelsen acknowledged Montreal's dangerous offence, he said that Toronto can compete if the players stick with their plan.
"It's a very hard team," Nelsen said. "Di Vaio's a great finisher, they've got the best Canadian player playing in the MLS at the moment in (midfielder Patrice) Bernier . . .
"But I think it's all about us and how we play and how we inflict our style and attitude on the game."
Also Tuesday, Toronto acquired midfielder Michael Thomas from Sporting Kansas City on Tuesday for a second-round pick in the 2015 MLS SuperDraft.
The 25-year-old Thomas played in seven MLS matches for Kansas City. He also made two starts in U.S. Open Cup competitions, including a 3-0 victory in the quarter-finals of last year's championship run.
Thomas began his pro career in Sweden.
Sporting KC acquired Thomas's rights from the San Jose Earthquakes and signed him on January 18, 2012.
"I've always liked Michael for a number of years," Nelsen said. "He's a very versatile player. He can play centre back, he can play centre midfield, he can play right back. And he's a lovely kid and a great professional.
"We've been kind of going for him for a while and luckily we got him."