The Detroit Tigers and Los Angeles Angels – who are known to be looking at starting pitchers – were among the clubs that had scouts in attendance Friday when Tampa Bay right-hander James Shields started against Seattle.

The Boston Red Sox, another club trying to add starting pitching, had a talent evaluator on hand as well. So did the New York Yankees, Pittsburgh Pirates, San Francisco Giants and Toronto Blue Jays.

Shields, 30, is having a below-average season by ERA+ but is appealing to clubs because of his track record and favorable contract. The Rays hold club options for 2013 ($9 million) and 2014 ($12 million).

The Tigers and Angels have interest in Phillies left-hander Cole Hamels, but Shields may be more attainable because of the possibility Hamels will sign a long-term deal in Philadelphia. The Tigers have had interest in Shields for years, sources say, and could have the catching prospects (Rob Brantly or James McCann) to entice the  Rays as part of a package.

Rays general manager Andrew Friedman isn’t shopping Shields, but the team’s low payroll necessitates that he remain open-minded to proposals for any player. The Rays wouldn’t rule out trading Shields within the division if that deal enabled them to get the biggest return. Friedman also would listen to offers for starters Jeremy Hellickson, Alex Cobb and Wade Davis, sources say.

The Rays and Jays have scouted one another’s farm systems in recent weeks; Toronto acquired starter J.A. Happ in a 10-player trade with Houston Friday, but it would surprise no one in the industry if Blue Jays GM Alex Anthopoulos struck another major deal before the July 31 non-waiver deadline.

-- Ken Rosenthal and Jon Paul Morosi