After an 11-day vacation in California, President Reagan returned to Washington last night to captain a team that apparently has decided it is better off not carrying the ball.

Reagan faces the difficult task of persuading Congress to agree to the use of U.S. forces to aid in the evacuation of embattled West Beirut, and on Tuesday he plans to travel to Baltimore for a speech aimed at breathing life into his flagging proposal for a "New Federalism."

But a year after his stunning victories in Congress--the promised prelude to a national economic recovery that has not come--the Reagan team has switched from playing offense to defense.

The limping economy remains the No. 1 concern. Despite Reagan's talk that the recession has bottomed out and the suggestion that prosperity is just around the corner, administration officials now do not believe that recovery will come any time soon, certainly not in time to help out in the fall elections.

And there is the certainty that there will be losses in those campaigns, the question being only how deep. White House political director Edward Rollins accompanied the presidential party to the West, spending his time working with the California campaigns. Reagan has staked his prestige on keeping the Senate seat there in the Republican column, but some advisers believe he may have wagered too much on that race even though Gov. Edmund G. (Jerry) Brown Jr. is lagging in the polls.

The strategy that is emerging is to keep Reagan above the fray in the campaign, with Vice President Bush doing the heavy-duty campaigning. The tactic stems partly from an effort to put distance between Reagan and whatever losses the party suffers and partly from a recognition that the president, because of his own slide in the polls, may not be a great deal of help to the candidates.

There is also the feeling that a heavy schedule of appearances at big fund-raisers would only serve to reinforce Reagan's image of being the rich man's president.

There was something of a sense of relief the other day when the June unemployment figures were released, indicating that the record post-World War II level of joblessness of the previous month had stayed the same, and not gone higher as some economists had predicted.

In his brief public appearances down from the mountaintop, Reagan has again spoken of the midwestern bankers who decided to lower their interest rates, seeming to suggest that if only bankers across the nation would do the same, the problem would be solved.

Administration officials, however, say they do not believe that interest rates, considered the linchpin to economic recovery, remain high simply because bankers have made the decision to keep them there. They feel that they still face a problem of "psychology" in the marketplace, the feeling that the federal government still has not taken strong enough action to keep spending down.

One administration official suggested this week that the markets are looking for the White House and Congress to deal with the unrestrained growth of Social Security and other entitlement programs.

But, he added quickly, that is not a matter that the Reagan administration intends to tackle before the elections. The effort now, rather, is to repair some of the damage resulting from administration positions on Social Security during budget battles last spring.

The reality, one administration official observed pragmatically, is that the elections are only 100 days away and in that time there is little that Reagan can do to affect the economy short of imposing a credit control, and that, he noted, goes completely against Reagan's philosophy.

Reagan and his aides have floated trial balloons indicating an interest in a flat-rate tax and renewed determination to pursue a constitutional amendment requiring balanced federal budgets. But an administration official said those are long-term initiatives, not advanced as cures for the current problems.

Between now and November, the determination, it would appear, is to hold tight and tough it out.

Aides plan to get to work on the job of refurbishing Reagan's image by getting him out into the country more for what they describe as "people events."

These will be similar to the one in Los Angeles recently where the president, in the setting of a senior citizens' home, sought to counter the perception that he was for dismantling Social Security. He charmed and delighted the residents, calling them members of "my own generation."

Political candidates are likely to be included in these events, under the plans being formulated, but they will not be the focus.