Todd Coffey‘s earned-run average (36.00) is inflamed. Turns out, so is his knee.

Coffey was placed on the 15-day disabled list with anterior knee inflammation and left-hander Ted Lilly was activated from the DL so he can start tonight’s game against the San Diego Padres.

“It’s definitely a situation where if we were later in the season and it had to be pushed through, that’s no problem,” Coffey said. “It seems kind to silly right now to man up, push through something that we could get completely knocked out, ready to go 100 percent.”

It also seems silly to demote Josh Lindblom. The right-hander can be optioned to the minor leagues but is pitching as well as anyone in the Dodgers’ bullpen, having allowed one hit and no runs in four appearances. Coffey, who has surrendered two runs without recording an out in back-to-back outings against the Padres, does not have a minor-league option.

But someone needed to be removed from the active roster Saturday to make room for Lilly and Coffey’s knee gave the Dodgers their out.

Manager Don Mattingly was asked to address the “suspicious” timing of the transaction prior to the game.

“We know (Coffey) hadn’t been pitching 100 percent,” he said. “We have a choice to either send Josh down, or get this guy healthy. He’s not at the point where he’s going to need surgery, but he’s not at the point where he’s healthy.”

Coffey said he first noticed the problem three days ago. Mattingly joked that he noticed a problem when it took Coffey 10.2 seconds to sprint in from the bullpen Friday night, according to the Dodger Stadium scoreboard. “I think we had him at like 9-something the other day.”

His pitching problems date back several weeks. In his last nine appearances, including spring training, Coffey has allowed two or more hits seven times. He’s allowed at least one run six times in that span.

The injury directly impacts Coffey’s back leg, the one he uses to push off the pitching rubber. Coffey said that affects the movement at the end of his pitch by only a few inches, but that can make all the difference.

“You’re talking about this much off is between a strikeout and a hit ball,” he said. “The finish at the end does not allow me to get that end motion to get what I need on the end of the pitch. The velocity’s there — 93, 95. It’s just that last little movement at the end.”

Coffey will have three days of rehab with no baseball activity otherwise, followed by bullpen sessions and “maybe two” minor-league games before his next major-league appearance. Fifteen days on the disabled list “should be plenty sufficient,” he said.

Both he and Mattingly dismissed the notion that Coffey’s weight was a factor in the knee injury. The pitcher is listed as 6-foot-4 and 280 pounds in the team media guide and will not be asked to lose weight, Mattingly said.