TAMPA — In the aftermath of yet another loss — the Red Sox’ fourth straight and fifth in the last six games — Wednesday night in Toronto, veteran reliever Mike Timlin voiced a popular sentiment in a somber visitors’ clubhouse.

“We need to have momentum going into the playoffs,” said Timlin, who had helped contribute to the Blue Jays’ four-run eighth inning in the Sox’ 6-1 setback. “Every team does.”

Well, yes and no.

Actually, recent baseball history is littered with successful post-season teams who had little or no momentum established when the playoffs began. There is enough precedent, in fact, to suggest that a team’s September performance has no impact on their play in October.

Take the 2005 Chicago White Sox as a textbook case.

The White Sox opened a sizeable lead over the Cleveland Indians early, then sputtered badly in September. On the morning of Sept. 7, the first-place White Sox held a healthy 9½-game lead over the Indians.

But then the White Sox dropped 10 of their next 14 games and by Sept. 22, the White Sox margin had nearly evaporated. They led the Indians by a mere game and a half — the same margin the Red Sox now hold over the Yankees in the American League East.

In the final 10 days of the season, the White Sox reversed field, the Indians ran out of gas and Chicago wrapped up the A.L. Central title. Then, as if to disprove the notion that a team’s success in the post-season is tied closely to its play in the final month of the season, the White Sox obliterated the competition and won their first World Series in almost 90 years.

The White Sox swept the Red Sox three straight in the Division Series, took care of the Los Angeles Angels of Anaheim in five in the ALCS and swept the Houston Astros in the World Series.

Total postseason games played: 12. Total victories recorded: 11

It was more of the same last fall — in both leagues.

Having led the A.L. Central from the beginning of the season, the Detroit Tigers faltered badly down the stretch. They were 12-16 in the month of September, a month that culminated with five straight losses to close out the regular-season schedule.

The final three losses were the most ignominious of all, since they came at the hands of the lowly Kansas City Royals. That sweep by the Royals, who lost 100 games, cost the Tigers the division title on the final day of the season. The Minnesota Twins, who seemed out of playoff contention altogether the previous month, overtook the Tigers and were crowned champions, gaining home-field advantage in the playoffs.

But the same Twins who were 15-7 in their final 22 games and 6-3 in their final nine were also summarily swept out of the Division Series by the Oakland A’s in three straight. End of story, end of season.

And those slump-ridden Detroit Tigers, the same ones who couldn’t manage one measly win in three tries against the Royals? They knocked off the Yankees in four in the ALDS, then swept the A’s four in a row to win their first pennant since 1984.

The Tigers then lost the World Series, but that was mostly because their pitchers set a new low for post-season fielding ineptitude.

As for the team that knocked off the Tigers? That would be the St. Louis Cardinals, whose 83 wins were the fewest by a National League champion since the 1973 New York Mets.

The Cardinals didn’t exactly ramp up for the postseason, either. They lost 9 of their last 12 games, including a remarkable seven in a row at one point, barely managing to hold off the second-place Houston Astros.

On Sept. 20, the Cardinals had a seven-game edge over the Astros; on the final day of the season, that margin had been whittled to just a game and a half. (The Cardinals played just 161 games, accounting for the season-ending half-game difference in the standings.)

As the lowest-seeded division winner in the N.L. — the Cards actually had a worse record than the wild-card Los Angeles Dodgers, but MLB rules stipulate that a division winner is seeded higher than a wild-card entrant, regardless of record — St. Louis had to go on the road in the NLDS.

They made quick work of the N.L. West champion San Diego Padres, beating them in four games before holding off the New York Mets in a thrilling NLCS that went the full seven games.

From there, the Cards went on to beat the Tigers in just five games to become the 2006 champs.

No one knows, of course, how the 2007 postseason will play out. But if recent history is a guide, the month of September won’t have much impact on it.

smcadam@projo.com