The AL West may have missed its chance to leave the Seattle Mariners behind.

Seattle has been under .500 for most of the season, but now the Mariners (31-29) lead the division after six straight victories. They’ve made this run without slugger Cal Raleigh, who was hitting .161 when he went on the injured list over two weeks ago.

It doesn’t take much to shake up the standings in the AL West. The Mariners’ streak included a three-game sweep this past week over the Athletics. The A’s were in first place, but have lost seven of their last nine. Houston has won eight of its last 12 to pull back into contention, just 4 1/2 games out of first place. The whole division is separated by 8 games, the top three teams by 2 1/2.

Despite Raleigh’s absence, the Mariners are fourth in the American League in home runs, but pitching is what has driven this recent run. Seattle has held opponents to two runs or fewer in five of its last six games.

The same five starters have made 57 of Seattle’s 60 starts. Bryan Woo (3.44), Logan Gilbert (3.69), George Kirby (3.77) and Emerson Hancock (2.78) all have ERAs among the top 25 in the AL. Luis Castillo (5.53) lags behind the other four starters, but lately Seattle has been using him in sort of a tag team with Bryce Miller, with one starting and the other coming out of the bullpen.

In a 9-2 win over the Athletics, Castillo pitched four scoreless innings and then Miller threw the last five. On Sunday against Arizona, Miller started and went five innings, then Castillo worked the last five and Seattle won 3-2 in 10.