"He's better than he was yesterday, but he's still day to day," McClendon said prior to Sunday's series finale with the A's.
Cruz took batting practice on Saturday and is OK swinging the bat, so he could be available for pinch-hitting duties. But the leg limits his mobility.
"We've just got to get him running," McClendon said. "He's doing some drills now. He's getting better. My hope is to have him for the Texas series. We'll see."
Cruz has hit .417 with five home runs and 10 RBIs in 12 games against his former Rangers team this season.
Left fielder Franklin Gutierrez is in much the same boat with a tight right groin muscle. He was taken out of Friday's game against the A's in the second inning and hasn't played since. Gutierrez was riding a stationary bike before Sunday's game, but still hasn't been able to take batting practice.
"He's getting better, too," McClendon said. "My hope is to have him for the Texas series as well."
• Utility player Shawn O'Malley was back in the lineup Sunday after going 5-for-6 (.833) with three walks, a home run and double in his first two games as a September callup and McClendon indicated the 27-year-old will continue getting time to show what he can do.
"He's an interesting guy," McClendon said. "He's certainly paid his dues and he's going to get a long look. We'll see what happens. Obviously, he's not an .800 hitter. He'll have his moments. I like what he brings to the table. By no means is he the second coming of Babe Ruth. We have to be patient with him. He's going to make some mistakes. But I like his speed, he's a switch-hitter and he provides a lot of versatility."
• According to Elias, O'Malley joined Steve Henderson (1983) as the only Mariners to reach base four times in each of their first two games with the team.
• The Mariners still haven't announced a starter for Wednesday's game against the Rangers. If Vidal Nuno isn't needed in the bullpen in the next few games, he could return to the rotation to take the spot held by Edgar Olmos, who lasted just 1 1/3 innings in his second spot start.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB, read his Mariners Musings blog, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.