It's been a couple of years since I examined how the rotation was managed...
This is one of the most important things a manager does - I would
suggest that it's far more important than 90% of what the conversation
about managers generally covers. As you will recall, the team came out of spring training with Marcum, Romero, Morrow, Tallet, and Eveland in the rotation. Gaston went with Marcum on Opening Day and just turned the five of them over for the first few weeks... (if the starter's name is in CAPS, the Jays won the game)
Marcum, TALLET, ROMERO, MORROW, EVELAND (off-day after Marcum)
MARCUM, Tallet, ROMERO, Morrow, EVELAND
Marcum, Tallet, Romero, MORROW, EVELAND
Brian Tallet went on the DL and was replaced by Brett Cecil. Gaston simply inserted Cecil in Tallet's spot and kept turning the five starters over...
Marcum, CECIL, Romero, Morrow, Eveland (off-day after Marcum)
Marcum, Cecil, ROMERO, MORROW, Eveland
MARCUM, CECIL, ROMERO, MORROW, EVELAND
MARCUM, Cecil, ROMERO, Morrow, Eveland
MARCUM, CECIL, ROMERO, MORROW, Eveland (off-day after Marcum)
MARCUM, CECIL, Romero, Morrow, Eveland
That was all for Dana Eveland, and a conveniently located off-day allowed Gaston to get by with just four starters for one turn through the rotation
MARCUM, CECIL, Romero, Morrow (off-day after Morrow)
Brian Tallet came off the DL and made his brief return to the rotation.
MARCUM, CECIL, ROMERO, MORROW, Tallet (off-day after Marcum)
Marcum, CECIL, ROMERO, Morrow, Tallet
Until Jesse Litsch was ready to go, sending Tallet (permanently) to the bullpen
Marcum, CECIL, Romero, Morrow, Litsch
MARCUM, Cecil, ROMERO, MORROW, LITSCH (off-day after Romero)
Marcum, Cecil, Romero, MORROW, Litsch (off-day after Marcum)
MARCUM, Cecil, Romero, Morrow, Litsch
Marcum, CECIL, Romero, Morrow, Litsch (off-day after Morrow)
With just one turn through the order left before the Break, Shaun Marcum was shut down and Mark Rzepczynski filled in
RZEPCZYNSKI, CECIL, Romero, MORROW, Litsch
The Jays got 4 off-days at the Break, and Gaston: a) adjusted the sequence of starters, and b) ran through six different starters before turning the rotation over. For one thing, there was a double-header to cope with:
ROMERO, MORROW, MARCUM, Cecil/LITSCH, Rzepczynski (Cecil/Litsch was the July 25 DH)
Another off-day allowed him to give Morrow some extra rest
Romero, MARCUM, CECIL, Litsch, MORROW (off-day after Romero)
And Brad Mills came up to help out as well. Gaston ran through another six man sequence.
ROMERO, MILLS, MARCUM, Cecil, Litsch, MORROW
That would be the end of Jesse Litsch in 2010. Brad Mills was already in place to take his spot. After the next off-day, Gaston bumped Mills back a day or so to keep Cecil on regular rest but again gave Morrow additional rest
ROMERO, Marcum, CECIL, MILLS, MORROW (off-day after Marcum; off-day after Morrow)
He used the second off-day to give Cecil some additional rest, and skips Morrow entirely (that last start was his 17K one-hitter) the next time through. Rzepczynski comes up to take Morrow's start.
Romero, Marcum, MILLS, RZEPCZYNSKI, Cecil
Rzepczynski stays in the rotation as Mills returns to AAA.
ROMERO, MARCUM, Morrow, Rzepczynski, CECIL (off-day after Rzepczynski)
Romero, Marcum, MORROW, Rzepczynski, CECIL
Romero, MARCUM, MORROW, Rzepczynski, Cecil
ROMERO, Marcum, Morrow, Rzepczynski, CECIL (off-day after Marcum)
At this point, Morrow is shut down for the year. Shawn Hill takes his place - Gaston uses that and the off-day to get Brett Cecil some extra rest.
ROMERO, MARCUM, Rzepczynski, Hill, Cecil
Kyle Drabek comes up and the team goes to a six man rotation. Gaston again gets extra rest for Cecil by inserting Drabek before him.
Romero, MARCUM, Rzepczynski, Hill, Drabek, Cecil
He flips Drabek and Hill, presumably to keep the younger pitcher as close as possible to his normal rest
ROMERO, Marcum, RZEPCZYNSKI, Drabek, HILL, CECIL
He flips Cecil and Hill, giving Cecil the start against the Yankees (Cecil is 3-0, 2.22 against the Yankees this season.)
ROMERO, MARCUM, RZEPCZYNSKI, Drabek ......... yet to be played - we'll see [Cecil, Hill
Romero, Marcum, Rzepczynski,]
While in the past Gaston (and Gibbons before him) would take advantage of off-days to bump the rest of the starters back a day or two in order to keep Roy Halladay humming along on his regular rest (which over the course of a season would also ensure two or three extra starts for Halladay) Gaston did none of that this season - he seemed more interested in finding ways to get additional time off for Morrow and, later on, Cecil.
3 days 4 days 5 days 6 days 7+ days Off Rotation
Romero 0 16 8 6 0 1
Marcum 0 15 9 4 0 2
Cecil 0 12 9 3 2 1
Morrow 0 11 10 2 2 1
Rzepczynski 1 3 3 0 1 3
Eveland 0 6 2 0 0 1
Litsch 0 3 3 1 1 1
Tallet 0 2 0 1 0 2
Mills 0 1 0 0 1 1
Drabek 0 0 1 1 0 1
Hill 0 1 0 0 1 1
https://www.battersbox.ca/article.php?story=20100929142044806