John Edward Lannan (born September 27, 1984) is an American former professional baseball pitcher who currently serves as the Major League mental performance coach for the Toronto Blue Jays.

He began the year for the high-A Potomac Nationals going 6–0 with an earned run average of 2.13 and was promoted to the Double-A Harrisburg.

[3] Lannan picked up his first Major League win, in his second start, six days later, in which he held the Cincinnati Reds hitless through three and scoreless through five inning before allowing two runs in the sixth.

His 2010 season started off poorly, allowing seven hits, three walks, and five runs in only 32⁄3 innings against the Philadelphia Phillies on Opening Day.

The Nationals later recalled Lannan in August to take the place of the injured Stephen Strasburg (who later had Tommy John surgery).

On July 22, 2011, Lannan hit his first career home run off Hiroki Kuroda of the Los Angeles Dodgers.

It was a two-run home run, giving the Nationals a 3–0 lead, en route to a 7–2 win at Dodger Stadium.

[8] Lannan made a minor change in his mechanics in AAA, resulting in a sharper downward angle on his throwing motion.

At AAA, he tossed three complete games (two shutouts) over 24 starts with a 9–11 record, 86 strikeouts, and a 4.30 earned run average.

In total, he started just six games (32+2⁄3 innings pitched) for Washington, resulting in a 4–1 record in addition to 17 strikeouts and a 4.13 earned run average.

Phillies general manager Rubén Amaro, Jr. commented,He is a solid veteran who has always been a strike thrower ... it is very important to have as much starting pitching depth as possible.

Lannan was happy to sign with a northeast team due to their hard-nosed mentality, but previously, he had a "unique" history with the Phillies including being ejected in his major league debut, which he made at Citizens Bank Park, during which he hit Chase Utley and Ryan Howard in consecutive at bats.

[15] On August 20, 2013, the Phillies announced that Lannan would miss the remainder of the season with what their assistant general manager Scott Proefrock called a "ruptured tendon", which the team physician said would require surgery.

[20] On November 18, 2014, the Colorado Rockies signed Lannan to a minor league contract that included an invitation to spring training.

He made 25 appearances (19 starts) for the Triple–A Omaha Storm Chasers in 2016, compiling a 7–8 record and 5.24 ERA with 55 strikeouts across 132+1⁄3 innings pitched.

[24] On March 8, 2021, Lannan was announced as the mental performance coach for the Buffalo Bisons, the Triple-A affiliate of the Toronto Blue Jays.