Initially, Ruiz elected not to play in the 2009 World Baseball Classic, but after receiving a call from Martín Torrijos, the President of Panama, he agreed to play for the Panamanian team.
Early in the season, he suffered a muscle strain in his right oblique, which lost him playing time while on the disabled list.
Also early in the season, there was debate as to who should be the Phillies starting catcher, Ruiz or Chris Coste.
Rob Neyer summarized the debate and ultimately endorsed Ruiz when he wrote, 
It's Ruiz who has established himself as the superior hitter, almost solely because we expect him to draw more walks than Coste.
Yes, Coste does have superior stats as a major leaguer ... But he is 36, and with a couple of exceptions he's not fared all that well in the high minors.
Meanwhile, Ruis [sic] is six years younger and he's been relatively impressive in the high minors.

— Rob Neyer, SweetSpot Blog – ESPN, May 26, 2009
Ultimately, Ruiz was the regular starter.
He finished the season on a hot streak; over the last 24 games, he hit .355 with 9 doubles, 1 home run, 11 RBIs, and .446 on-base percentage (OBP).
In late September, he missed a week of games with inflammation in his left wrist.
Despite his missed time, he started 100 games and set career highs in home runs (9) and base on balls (47), as well as posting a .255 batting average and 43 RBIs.
Moreover, he walked more times than he struck out, a rare feat among modern major league hitters.
In the postseason, he led the team with a .341 batting average, and recorded a .491 OBP, having reached base in each of the Phillies' 15 games, which perpetuated the usage of his nickname "Señor Octubre".
Marcus Hayes of the Philadelphia Daily News wrote that Ruiz is "... the Phillies' Senor Octubre, a No.
8 hitter who hits like John Buck in the regular season, then turns into Johnny Bench come autumn."
Initially, Ruiz elected not to play in the 2009 World Baseball Classic, but after receiving a call from Martín Torrijos, the President of Panama, he agreed to play for the Panamanian team. Early in the season, he suffered a muscle strain in his right oblique, which lost him playing time while on the disabled list. Also early in the season, there was debate as to who should be the Phillies starting catcher, Ruiz or Chris Coste. Rob Neyer summarized the debate and ultimately endorsed Ruiz when he wrote, 
It's Ruiz who has established himself as the superior hitter, almost solely because we expect him to draw more walks than Coste. Yes, Coste does have superior stats as a major leaguer ... But he is 36, and with a couple of exceptions he's not fared all that well in the high minors. Meanwhile, Ruis [sic] is six years younger and he's been relatively impressive in the high minors.
— Rob Neyer, SweetSpot Blog – ESPN, May 26, 2009
Ultimately, Ruiz was the regular starter. He finished the season on a hot streak; over the last 24 games, he hit .355 with 9 doubles, 1 home run, 11 RBIs, and .446 on-base percentage (OBP). In late September, he missed a week of games with inflammation in his left wrist. Despite his missed time, he started 100 games and set career highs in home runs (9) and base on balls (47), as well as posting a .255 batting average and 43 RBIs. Moreover, he walked more times than he struck out, a rare feat among modern major league hitters. In the postseason, he led the team with a .341 batting average, and recorded a .491 OBP, having reached base in each of the Phillies' 15 games, which perpetuated the usage of his nickname "Señor Octubre". Marcus Hayes of the Philadelphia Daily News wrote that Ruiz is "... the Phillies' Senor Octubre, a No. 8 hitter who hits like John Buck in the regular season, then turns into Johnny Bench come autumn."
Carlos Ruiz (baseball)