I am planning on making this fish recipe from M Stewart Living - nice and easy - except I just discovered I don't have any fresh tomatoes

[DIDN'T get any at store as for some reason thought I did. Lovely.] Any opinions as to feasibiliy of dumping in canned tomatoes.....???? I am not at all a "wing it" sort of cook......
Cod Provencal
4 cod fillets
1 lemon, halved
1/8 teaspoon coarse salt
Freshly ground pepper
2 T evoo
2 small onions chopped
2 garlic gloves, thinly sliced
1 small zucchini, thinly sliced
4 medium ripe tomatoes, thinly sliced
2 tsp fresh thyme
1) Preheat oven to 400. Place cod fillets in a nonreactive dish and squeeze lemon on top. Refrigerate for 30 minutes. Sprinkle with 1/4 tsp salt and season with pepper.
2) Heat 1 Tbsp oil in medium Dutch oven over medium heat. Add onions; cook until golden brown, about 12 minutes. Add garlic, cook for 3 minutes. Remove from heat. Top with half the zucchini, tomatoes, and thyme. Drizzle with 1 1/2 tsp oil, sprinkle with 1/4 tsp salt, and season with pepper. Add cod and remaining zucchini, tomatoes, thyme, oil and salt. Season with pepper
3) Bake, covered for 10 minutes. Baste with juices, then bake, uncovered, for 15 minutes more.