It is February, the Toronto Maple Leafs are sitting in a playoff spot, and they should be able to keep Florida, Tampa, and Winnipeg in their rear view mirror. There is a segment of Leaf Nation convinced that the team is in the midst of a goalie controversy, and those would be the people who set their expectations for James Reimer at the highest peak. In January Gustavsson was 7-3-1 with a 2.08 GAA and a .926 save percentage, ergo he has been the starting goaltender. Reimer has struggled since the concussion, with a few scattered good games and a number of bad games. However Gustavsson's quality play has made it difficult for him to get back in the net and get into a rhythm. It's not like Toronto is experiencing anything like the madness in St.Louis with two red hot keepers in Halak and Elliot.
If you happened to think that Reimer would challenge for the Vezina this season, then you would be more likely to think there is a goalie controversy in TO right now. But there is no controversy, just a team with two young goalies playing the hot hand. That's how it should be if you are fighting for a playoff spot. Go with whoever is getting you wins, and if that's neither than alternate starts until somebody gets hot. It is a standard formula used successfully for decades, across generations. Goalies tend to take longer to develop, often with greater variance in their performance than position players. You need to be patient with young goalies and know how to use them properly. You could even argue that the best course would be to send Reimer to the minors to get starts, if the nature of his contract allows him to be sent down without clearing waivers.
Last night Gustavsson blew a large 3rd period lead and Toronto lost. Tonight Reimer is starting against the same team, and has a shutout after two periods. So what happens if Reimer starts playing well and Gustavsson starts sitting on the bench for a few weeks because of 1 bad game? Alternating starts is the best way to keep both guys fresh so long as both are winning hockey games.