Bartolo Colon’s next stop on the comeback trail is Anaheim

Reporting from Kansas City, Mo.

The Angels will get a new look at an old friend this weekend. The New York Yankees are scheduled to start right-hander Bartolo Colon against his former teammates Sunday.

After winning 21 games and the Cy Young Award with the Angels in 2005, Colon went 14-21 with a 5.18 earned-run average for three teams over four injury-plagued seasons, pitching himself out of baseball. He didn’t play in the big leagues last season, but after watching Colon top 93 mph with his fastball in the Dominican winter league, the Yankees coaxed him back with a minor league contract and a chance to compete for a spot in their rotation.

But there’s more to Colon’s comeback than just a talented guy making the most of another chance.

Joseph R. Purita, an orthopedic surgeon who runs a regenerative medicine clinic in South Florida, told the New York Times that he and a team of Dominican doctors treated Colon 15 months ago, using a novel procedure in which they took fat and bone marrow stem cells from the pitcher and injected them back into his elbow and shoulder to repair ligament damage and a torn rotator cuff.

Although Purita has treated patients with human growth hormone in the past, he told The Times he did not give it to Colon. HGH is banned by baseball, and MLB spokesman Pat Courtney confirmed the commissioner’s office is investigating the pitcher’s treatment.

There’s no debating Colon, 38, who relies mainly on a late-breaking two-seam fastball, is a rejuvenated pitcher.

He evened his season record at 3-3 Monday by blanking Oakland on four hits, his first shutout and complete game since 2006. He hit 95 mph on his final pitch in that one, and in 66 1/3 innings this season he has struck out 62 and walked 15 — the best ratio of his career.

His 1.10 WHIP — walks plus hits per innings pitched — is also a career best, and his .234 opponents’ batting average is the lowest since 2000. His 3.26 ERA is better than in his Cy Young season.

“We’ve seen bits and pieces, but it looks like he has his velocity back. And he’s healthy. That’s a couple of things that plagued him the last couple of years,” Angels Manager Mike Scioscia said. “He’s pitching very well.”

Youth is served

The lineup the Angels started in Wednesday’s road-trip finale included four rookies and another player, centerfielder Peter Bourjos, with less than a year of major-league experience.

Scioscia said such lineups have led to some growing pains.

“There’s been inconsistency. And I don’t think there’s any mystery why there’s been inconsistency,” he said. “We’ve had a lot of guys maybe hitting in spots in the order they aren’t probably best suited for. We’re trying to get a little continuity there. And we’ve got some kids that are trying to learn major league pitching.”

Help is on the way. The Angels expect to activate Howie Kendrick, the team’s leading hitter, from the disabled list Saturday. He hasn’t played since May 20 because of a strained hamstring. Rookie Alexi Amarista will likely be sent down to Triple A.

Also, outfielder Vernon Wells, on the disabled list since May 10 with a strained groin, was scheduled to take batting practice Thursday at Angel Stadium. He could be sent out on a minor league rehabilitation assignment as early as Saturday.

Kazmir’s turn

Left-hander Scott Kazmir is scheduled to make his third rehab start for Triple A Salt Lake on Friday in Sacramento. Kazmir, who has struggled with mechanical issues, has given up 16 runs in four innings in his first two minor-league appearances. Opponents are hitting .421 against him.

kevin.baxter@latimes.com