KANSAS CITY — Royals left-hander MIke Montgomery, acquired earlier this month from the Cubs for catcher Martin Maldonado, continues to build up his arm strength as a regular part of the rotation.

And Montgomery’s final line Tuesday night — 4 1/3 innings, seven hits, four earned runs, one walk and four strikeouts — was a little misleading. Two of the key hits against Montgomery in a 9-2 loss to the Blue Jays at Kauffman Stadium were the result of simple misfortune.

Montgomery gave up two runs on four singles in the first, the last an RBI hit by Vladimir Guerrero Jr. on a ground ball that would have been fielded by shortstop Humberto Arteaga if it hadn’t hit the lip between the infield grass and dirt. That caused the ball to skid under Arteaga’s glove and into center field.

In the fifth, the Jays had the bases loaded and one out when Montgomery sent a cutter in on the hands of Freddy Galvis, shattering his bat. But Galvis nonetheless blooped a two-run single over the infield for a 4-0 lead.