Updated

The trade deadline is approaching — and with each loss, the Philadelphia Phillies look more and more like a team with an uncertain future.

Alex Avila's two-run double in the fifth inning put Detroit ahead, and Doug Fister pitched eight impressive innings for the Tigers in a 2-1 victory on Friday night that sent the Phillies to their season-worst sixth straight loss.

Manager Charlie Manuel was asked before the game about the possibility his team could trade some key contributors soon, and afterward he admitted his players might be a bit unnerved by all that talk.

"I think it might be bothering them. We've got a lot of young, inexperienced players, and they get concerned about where they are going to be playing and who is going be traded," Manuel said. "That didn't used to be the case, but things are all over the place now and they read it all."

Cole Hamels (4-13) was trying to protect a 1-0 lead for the Phillies when he allowed the bottom of Detroit's batting order to break through. After a one-out walk to Hernan Perez, Ramon Santiago and Avila hit back-to-back doubles.

"That was obviously unacceptable on my part," Hamels said. "I can't walk a rookie leadoff hitter in that situation. I have to challenge him. And then I get to Avila, and I throw a 2-0 changeup, which was just stupid. That was the worst possible pitch to throw in that situation, with him at the plate and with that count."

Santiago was playing third base in place of slugger Miguel Cabrera, who hasn't played since Monday because of an injured left hip.

Fister (9-5) allowed three hits and an unearned run. Joaquin Benoit pitched the ninth for his 10th save in 10 chances.

Darin Ruf grounded out with a man on third to end it.

"It was just a good all-around baseball game," Avila said. "Good pitching, a lot of tense moments — a fun game."

The Tigers were without Cabrera, outfielder Torii Hunter (left Achilles) and second baseman Omar Infante (sprained left ankle). The Phillies were short-handed, too, with first baseman Ryan Howard and outfielders Domonic Brown and Ben Revere on the disabled list.

In the middle of their latest loss, the Phillies announced left-hander Cliff Lee would miss Saturday night's start because of a stiff neck.

"Just more bad news," Manuel said. "I hope I get to the hotel OK. I've got two doors in my room and I'm locking the hell out of them. I know that."

Philadelphia took a 1-0 lead with a third-inning run off Fister. John Mayberry Jr. reached on an error by Perez, the second baseman. One out later, Carlos Ruiz hit a single, and Michael Young followed with an RBI single to snap an 0-for-12 skid.

But Fister struck out the next two hitters to get out of that jam. After Ruf's single in the fourth, no more Phillies reached base until the eighth.

Young drew a two-out walk in the eighth, but Fister retired Kevin Frandsen on a groundout and walked off to an ovation from the Comerica Park crowd.

Fister walked one and struck out six.

Benoit allowed a leadoff single by Jimmy Rollins. With one out, Rollins stole second, and with two outs, he stole third. But the Phillies couldn't get him home.

Santiago had a nice all-around game. Young led off with a grounder toward the hole between Santiago and shortstop Jhonny Peralta, and Santiago made a diving stop to retire the Philadelphia third baseman.

In the fifth, Santiago's double down the left-field line brought Avila to the plate in a second-and-third situation. Avila, who was hitting .185 entering the game, hit a drive to the gap in left-center to score both runners.

Hamels allowed two runs and six hits in seven innings. He walked three and struck out six.

NOTES: Philadelphia's Delmon Young was hitless in his return to Detroit, where he was the MVP of last year's AL championship series for the Tigers. ... Detroit's Max Scherzer (14-1) faces Philadelphia's Raul Valdes (1-0) on Saturday night.