Backlund was out over four weeks with a grade 2 medial collateral ligament sprain suffered on Feb. 7 against the Columbus Blue Jackets.
The 23-year-old has three goals, an assist and a minus-1 rating in eight games with the Flames.
Baertschi started the 2012-13 season with the American Hockey League's Abbotsford Heat, playing 21 games, with six goals and 12 assists. He joined the Flames for the start of the NHL season but suffered a hip flexor injury that forced him to miss 11 games.
The 20-year-old has an assist and a minus-2 rating in 10 NHL games.
Baertschi was Calgary's first round selection, 13th overall in the 2011 NHL Entry Draft.