Bobby Valentine is in favour of big changes to baseball's system for September call-ups, and he's calling for revisions.

The Boston Red Sox manager said Friday that "I totally dislike it." He questioned the rules for the season's final month, when teams can expand their rosters to up to 40 players by promoting minor leaguers to either help in a pennant race or for evaluation toward the next season.

"This concept is a very old concept of expanding the roster and it should be revised, of course," Valentine said.

It's a time when some clubs carry far more players than others, with the only requirement for bringing someone up being that he's on the 40-man roster.

"You play the entire season to build a competitive advantage between your team and the competition and then it's thrown out the window in the last month of the season," Valentine said.

When asked whether one better option might be keeping rosters at 25 players but being allowed to change those 25 each day, Valentine didn't see much of a difference.

"Taxi squad or rotating roster would be a very similar situation," he said. "You could have five left-handed pitchers and always have three of them available. I don't think it's the right thing to do. I've always been a proponent of April expanded rosters so that you get to see guys in April play underneath the lights and pick a real team, and when you pick a real team you go to battle with that team through the post-season."

Boston plans to add lefty Rich Hill as he attempts to return from Tommy John reconstructive elbow ligament surgery last year. He made 17 relief appearances this season before going back on the disabled list June 10 with a strained flexor muscle in the troublesome elbow. Hill is 1-0 with a 2.63 earned-run average over 13 2/3 innings.

Valentine isn't even convinced players can show that much in brief stints in the big leagues late in the year, or even in spring training for that matter.

"It depends on who's evaluating and how you're evaluating. If you're evaluating on numbers, then it's very hard," he said. "If there's people out there in the stands or in uniform who know a ball player from a ball player, it's not so hard.

"I don't think it's proper to just reward people in September or spring training just on results. I think that's that old baseball adage that you can be fooled in September and spring training. It could be. It's not like they shorten the bases, raise the mound, turn off the lights."