ARLINGTON -- Vladimir Guerrero was swinging a bat with feeling in an early batting practice session on Friday at Rangers Ballpark in Arlington, yet another sign that things are getting better every day in the realm of Angels, Orange County variety.

"Vlad had a great workout, both running and swinging the bat," Angels manager Mike Scioscia said. "He turned it loose. He was killing the ball."

With Ervin Santana back in the rotation on the heels of a five-inning effort against Boston on Sunday and John Lackey making his season debut on Saturday against the Rangers, two of the big wheels are back in motion.

And Guerrero and Kelvim Escobar, two other forces of nature, are on the horizon.

Scioscia's excitement with Guerrero is tempered somewhat by his awareness that the big bopper probably needs at least a week to be ready for Major League pitching -- and that setbacks are always possible.

His torn right pectoral muscle is on the mend, but Guerrero knows he has to be careful not to do too much too soon. He watched that happen with Escobar, who was throwing in the mid-90s in an exhibition game a few days before the season opener and aggravated his right shoulder.

Guerrero felt the pull in his chest muscle making a throw from right field at Dodger Stadium in an exhibition game on April 2, one day before Escobar pushed himself too hard in San Diego.

"It's going to take some time," Scioscia said, referring to Guerrero. "He needs more BP. He got to where he took 25 to 35 swings and worked in the cage too."

Guerrero appeared in eight games, all as a DH, and was hitting .250 with one homer and three RBIs when he left the team in Seattle to be examined back home by Dr. Lewis Yocum. The club's orthopedist discovered the tear while reviewing an MRI.

Escobar, who will be eligible to come off the 60-day disabled list on June 4, has stepped up his program in extended spring training games along with Dustin Moseley, who delivered three solid starts before tightness in his right forearm sent him to the 15-day DL on April 18.

Moseley has the versatility to start or work out of the bullpen. Having excelled in middle relief in 2007, Moseley could fortify the 'pen when he returns given how superb Matt Palmer has been in winning all four of his starts.